The Ruger MK series of pistols are a bit harder to strip down/reassemble than say a Glock or something like that, but it's not so complicated that a person with normal skills can't do it. It's just a matter of understanding what you have to do, following the directions, and getting the parts worn together (they are tight at first).
Read and understand the directions. Every step is important. If they say point up or down, magazine in, magazine out..it's important. You can't skip that. And when it tells you to use a rubber mallet...use a rubber mallet. They're not kidding. The parts fit together that tight at first. You will not hurt anything.
Two things I had trouble with at first that aren't clear in the directions, or at least I didn't catch them. Removing the upper from the lower. I don't think you really need to do this...gunscrubber is your friend...but if you want to, you smack the rear of the upper to remove it, the front to reset it. After a few times you probably won't have to. I have one old Standard that just falls apart when I pull the mainspring out.
And in the reassembley instructions, at one point, it says "Let the hammer fall forward" or something along those lines. Well none of mine ever "fell" anywhere. They had to be pushed. A pencil, or a thin screwdriver work fine.
If you're going to use Gunscrubber, and I recomend it, make sure you (1) remove the grips first. (2) And if you're working on a 22/45 with it's polymer frame, be sure you use "polymer safe" Gunscrubber. It will work on metal frame guns too, so that's the safe one to buy anyway.
Most of the time I just flush them with gunscrubber, run a patch or two through the bore, and clean what I can reach with a Q-tip. I don't disassemble at all. Then when I do, I don't go much futher than pulling the bolt and flushing. The only times I've ever pulled the uppers were with old guns I bought used.
You'll need to put a few drops of oil here and there on the internals, and give it a good wipedown afterward of course.
For God so loved the world, that He gave His only begotten Son, that whoever believes in Him should not perish, but have everlasting life.
John 3:16 (NKJV)