Quicksteps to 3D print
Turn on Makerbot Replicator 3D printer.
The switch is on the lower back left hand side just above and to the right of the power cord.
Wait until the printer is finished starting.
Log into the Mac as student.
Start the Makerbot Print app.
If the app states that the printer is offline, quit the app and restart.
Transfer the file (typically a .stl file) to the Mac. (USB memory stick, log into email and download, if online CAD app start that app.)
In the Makerbot Print app, select new project, then add model, find your .stl file, select, and click open.
Position and scale model as desired.
Change the color of the filament if desired. Follow directions on printer menu. (Put end of filament roll not being used through holes in the rim of the spool to prevent tangling.)
Select Print to print your model.
Makerbot login
You do not need to be logged in to use the 3D printer. Login username and password are on the bottom of the Mac
From the manual -
You can use MakerBot Desktop without logging in, but logging in will allow you to access your MakerBot Cloud Library and additional features in the Explore, Prepare, and Store sections.
Clogged Extruder
If the normal technique of unclogging the extruder by unloading and loading the filament doesn't work -
First is the extruder under warranty contact Makerbot.
If not here is a video showing how to tear down and rebuild -