It's easy, take your time and keep organized and you can have it off in a minute or 3.

Might be a good idea to replace the belt too, if it needs it, also check for wear by the middle shaft. There is a little piece that is shaped like a D that can get worn out into a circle.

That belt needs to be tight so it doesn't "slip"

Here is the D shaped pulley piece:

http://www.marcospecialties.com/product.asp?ic=03-8086

Here is the proper belt, I've seen alot of machines where people substitute a playfield rubber, and it ends up failing in the long run:

http://www.marcospecialties.com/product.asp?ic=03-8614

Look around as I'm sure other shops sell this stuff too...

Good luck!

Give the optos a good cleaning before replacing the belt. Only if you visibly see the belt slipping should you bother to replace it (unless you don't have the right belt to begin with).

Sometimes you have to clean the optos Multiple times, with a few games in between. Had to do that on mine but in the end it was cheap, fast, and easy.

What should be used when cleaning optos ?

I didn't replace the optos... but getting the reel out is a little more of a pain than it looks initially.

It isn't a huge project but if I were you, I'd replace the pulley and belt while it is apart. Maybe look at a schematic and see if there are any other parts you could freshen up while you're there.