Tip:
Do not, for any reason take apart the rotary magazine!!!!!! If it works, leave it alone! If you take it apart, you will have hours and hours of entertainment, and likely not very much fun! And chances are you will not be able to get it back together (so it works), even after hours of fighting it.
If you must dis-assemble the rotary mag, take it to a professional, PAY whatever they want, and let them have the fun.
Unless something is broken, you can clean the 99 without taking it apart. If you take off the wood, it gets easier to reach some parts, but there is really no point in going further.