Cleaning the rangefinder on a Kiev II (first repair)

Hello, I want to clean the rangefinder window on a Kiev II. The rangefinder is very small and obscured by a bit of dirt. There are great references on the web:

http://www3.telus.net/public/rpnchbck/adjust rangefinder.html

and some others on forums. On the one hand, I feel like just attacking the thing with a screwdriver. On the other, I'm not so brave, since I've never done camera repair before. So, my question is how easy is this operation.

Thanks

Kiev II is rarer then other models. I would buy junk Kiev 4a or 4am and practice on it.

ah...good advice! Thanks