Caution: To get to the internals of this machine, you must get near the CRT. The CRT can be very dangerous if touched and can shock you causing serious and even fatal injury. Please be careful when opening these computers. It is a good idea to "uncharge" the CRT before operating inside the Mac.
The internal design of this machine is similar to that of the Mac Plus. To get inside the computer, you first need to remove the cover. Remove the programmer's switch from the side, set the computer face down, and remove the four Torx screws that hold the cover on. Pry the cover apart. Some special tools are made for this procedure. You should probably remove the little board attached to the end of the CRT. Take it off, but be very careful. You should not mess around with this unless the CRT is uncharged. Disconnect all of the cables from the logic board. Pull up on the logic board until it won't move, then tilt it over and remove it. Disconnect the last little cable from the logic board and then it is removed.
Hard Drive/Top Floppy Drive
Follow the instructions in the logic board section until you have removed the card attached to the CRT. Disconnect the cables that run from the hard drive or floppy drive to the other parts of the Mac. Take out two screws that hold the drive in place, and take the drive out. If it is a second floppy drive instead of a hard drive, there might be a little metal plate which you can remove.
Bottom Floppy Drive
Follow the instructions in the Hard Drive/Top Floppy Drive and also remove the logic board. You need to remove the top drive to remove the bottom drive. Remove the four screws in the bottom of the case that hold the drive in, and then remove it.
Information provided by Doug Brown.