These pin-face screws have threadlocker on them, so I recommend applying multiple doses rubbing alcohol (or acetone) to the edge of the screw and letting it soak in for a while. Be careful as these solvents can soften the paint, although my camera was OK afterward.

THIS STEP IS IMPORTANT because you can find reports on old internet forum posts from people who didn't do this and who broke these screws off! If you break them off you will have to drill out the old screw, cut new threads, and then find a suitable replacement flat screw--this would be a very difficult task and would require a drill press and tiny thread cutters.

After soaking for a five minutes or so, get your pin-face removal tool (I'm using Gearwrench #3151 pliers here) and loosen the screws. Once they are a bit loose, you can back them out with your hands, or a small rubber ball on the top of the screw.

If you close the door part way, you'll see these secondary strut screws.

On older models, these will be a slotted screw, and you will need a thin-bladed screwdriver. You may have to file a regular screwdriver of the appropriate width until it is nice and sharp and can fit in the slot. On newer models, it is a Philips screw.

When loosening these, you should put your hand underneath the lens and support it. This is so you can push down firmly on the screw without bending the struts.

Here is a picture of the bottom side with both screws removed. As you can see, there is some metal-on metal wear under the pin-face screw. When you put these back together, I recommend using a very light amount of grease on this flat surface, but make sure it doesn't get into the threads.

Peel back the old bellows from the metal front bellows ring, marked on the dashed red line. Fingernails work best for this, but it's glued down so it'll be a pain. You have to remove it before you can access the screws that hold in the back bellows ring. This step is maybe one of the most frustrating parts of this job so take your time and peel it off carefully.

Once it's free you can set it aside and spread out the old bellows so you have room to get in there with a screwdriver.

There are four screws in the four corners. They are hard to see, so you'll need a bright light. Like the first four screws, they are easy to strip, so push down firmly, use the correct screwdriver, and be careful with the alignment. They are steel screws threaded into the steel frame of the camera.

Once the old bellows is loose, you can pull it out and blow out any debris that's on the inside of the camera.

Note the battery wiring (top) and the channels in the light seals that allow air to move into the bellows when you open the camera. Pretty clever!

If your camera is working absolutely fine, you may want to just skip this step. Otherwise read on:

USING A LIGHTWEIGHT GREASE, lightly lubricate the moving parts on the door (marked in GREEN). Mainly, you want a tiny bit of grease on each thing that pivots when you open and close the door (four vertical green arrows).

DO NOT GREASE the vertically sliding spring assembly that is controlled by the winding lever (marked in RED).

You can also put a tiny bit of grease on the rangefinder lever sliders (two slots in the metal, top horizontal arrow) and on the door safety check (bottom horizontal arrow, grease the convex (right) side of the curved metal piece that rubs on the metal prong -- only use a tiny amount of grease here).

Next, use rubbing alcohol (or acetone) on a Q-Tip to clean the two sliding mechanisms (bracketed in red in these two images). Just clean the metal posts, then let the solvent dry.

Use a spray graphite lubricant, such as Lock Ease, and spray a little of the lubricant in a plastic bag. DO NOT spray it in the camera! Get some of the lubricant on a Q-Tip and wipe down the two metal slider rods. You don't need a lot, just get a good coating on them. You could also use plain old powdered graphite lubricant on a Q-Tip, instead of the spray kind.

A note on the sliding rod in the door: To move the mechanism down and expose the rod, cock the shutter with the film winding lever. DON'T pull it down by hand, or that thin cable can come off the pulley at the bottom—or worse, it can come off the pulleys in the top, which means you'll need to take the top cover off to fix it. For the bottom part of the rod, you can dab lubricant on the spring and it will get onto the rod.

A note on the sliding rod on the shutter mechanism: Pulling it down cocks the shutter. There is a tiny metal switch on the side of the sliding piece that fires the shutter. Using this, you can test your shutter. It should work normally and not stick once you lubricate it. If it still sticks, it may need the whole shutter replaced or the return spring replaced.

Unfortunately, the Chinese bellows I got for this camera on eBay are a little too small! They lacked the last fold that the original bellows had to fully wrap around. So instead of using glue as I originally planned, I had to use gaffers tape to make that last fold. Basically, it goes down into the "V" of the bellows all the way, then folds over onto the metal.

I cut the tape to be a little longer than the exposed metal area so that it will fully stop any stray light. I also had to cut out notches for the screws. A very annoying process but it will probably work just fine. Make sure to use high-quality gaffers tape for this, or a similar durable, sticky, light-blocking tape.

Install the new bellows into the camera, with the seam on the bellows facing the door.

Open the camera back and screw in the new bellows from the front, running the screw through the hole in the rear trim ring. Make sure you are using the countersunk screws, and not the flat ones from the front trim ring. Don't overtighten!

As with the rear ring, the bellows didn't have enough fabric! I guess they didn't quite copy the original bellows.

With the rear bellows ring now attached, it's safe to install the front ring. This tape job isn't the best--I ended up redoing it a couple times until I got a clean result.

Complete and ready to go, tested with a bright light and no holes. The shutter also works now too, thanks to that graphite lubrication.

Nothing like a few heavy books and gravity to compress those new bellows down.