It really is quite simple and i did it just today, what a difference.
First get your supplies, which includes a small screwdriver, some masking tape, and needlenose pliers (preferable but some other pliers will do), microfiber cloth, antistatic glass cleaner, a blower and maybe even some qtips.
First thing is there are three screws on the top plate, 1 on each side (just under the PC port on the one) and then one on the back next to the window bar. Get those out.
Then as look at the film advance, the top shiny gasket you are going to want to take off, this is where the pliers and masking tape come in. Put the masking tape on the gasket so you don't scratch it and then start to unscrew it using the pliers. Just be careful when you take it off completely as there is a smaller gasket that is under it that you could lose. It then goes top gasket, smaller gasket, film advance, and one more gasket, dont forget the order like i did
. Now the entire film advance/ shutter button should be off.
Onto the rewind knob, take it out so that you can grab the stem of the rewind knob with the pliers, (add tape if you are afraid of scratching it), and hold it tightly while you unscrew the rewind knob CCW.
Now the top plate should come off.
on the top plate there are the two outer pieces of glass. Slide out the front one (the one that has opaque glass), and saturate it in antistatic glass cleaner and let it sit in the microfiber cloth. Then look through the back outer piece that has the battery check and if neccessary clean that with the microfiber cloth.
Now you have the entire top plate off, before you remove the black plastic just look in the viewfinder and see if it is foggy, it probably isnt going to be, but if it gently remove the black plastic that covers the RF mechanism. It now should look like this (not my picture) : click here
If it has dirt and other crud in it just use to blower to get it off. If that doesnt work, go get some q-tips and lightly
put some on the glass cleaner around it, then go to work. If you can try to avoid cleaning the beam splitter (the glass at 45 degrees) as it can easily be knocked out of alignment and more importantly has to maintain its coatings. Now the elements should be clean, put the black plastic part on, slide the plate back in and start working backwards.