First of all,
You don't need to clean 'em very often. When there is a lot of gunk built up, I try to brush it out, and it usually suffices. I never clean the bore of a .22.
When it comes time to disassemble, just follow the manual. Exactly. It is VERY easy to take down and reassemble if you do that.
It all hinges on the little strut hanging down from the hammer. Look at the mainspring housing (the part you release by pulling down the latch lever in the backstrap). At its top there is a little depression, which is the top of the mainspring. The hammer strut must seat into that or you can't reassemble. You may find that when everything is almost together, you cat tip the muzzle up and watch to see that the strut has swung back so that it will slip into the depression as you swing the latch closed. That's all there is to it. If you do it wrong, you either can't close the mainspring all the way, or you can't pull the bolt back. Stop and try again. No big deal. Great guns- I've had a MkII since about 1981.