Took a leap of faith, and completely disassembled the lower on my S40 for cleaning. Took me about an hour to put it together again, but results are great - feels like a new gun. Lots of gunk came out, so it was worth it. After that, M40 only took about 15 minutes. Couple recommendations for people who are brave enough to try it: 1. Make sure you watch for springs and small parts flying off. 2. Spray the parts with Rem-Oil for lubrication - don't use too much. 3. Take your time. 4. Develop a pattern in which you put parts back together. Otherwise, it was great. Thanks to everyone who posted parts diagrams.