The front and guards come of by removing the gas cylinder lock nut (Use a gas lock wrench), next spin the lock counter clock wise, last is the gas cylinder that pulls straight out. By the way, pulling the gas cyclinder is a service item, so don't think as it as a smith only job.
As for the rear hand guard, get a guard tool or your going to do some damage getting the lock ring off the gaurd. As for the front guard, you just pick a side to spread the center piece ends straight to pull the metal from the guard.
Now on the dish washer method, Do not use heat drying cycle or you will crack the stock.
The dishwasher works great to pull most of the grease, strip the finish off the stock, and raise all by the most severe dents. If you have area's that are really grimed up (read ground in black) you will need to use mineral spirts to leach the last of it out. Don't try to use the dishwasher method more than once or you chance splitting the grain of the wood.
Once you do have the stock clean, let it dry out for at least a week before you start to final sand and refinish the stock.