Bear 1 - The first bear will be found in the spawn room. On the upper floor next to the RK5 wall-buy, to the left of it will be the bear in the dark on a box. You will now have to interact with it.
Bear 2 - Go to the side of the map with Stamin-up. Go to the part with the lander. Now go over to the broken lander which also has a box spawn. Right next to it will be the bear on the outside of the big gate on the wall. You will now have to interact with it.
Bear 3 - Go all the way up to the lander near Speed Cola. Now up there is a gobblegum machine and on the wall above it is the bear. You will now have to interact with it.
Song - Once you have done all three bears a song should start playing.