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.
To get to the logic board, you will need to remove the front cover. First, you should remove the PRAM battery located in a compartment in the back and the programmer's switch if it is there. The screws used are Torx screws so you will need the appropriate screwdriver. Set the Mac face down and remove the five screws that hold the case together. You will need to pry apart the Mac now and this may be tricky without a special tool. Disconnect the two cables connected to the logic board and pull the logic board out.
Remove the logic board. Remove the four screws at the bottom of the computer that hold the floppy drive in, and then remove the floppy drive.
Information provided by Doug Brown.