Yup - why not screw it up completely?
Agreed. Camera repair is not something you can do at home. It requires specialized tools and training.
I do my own car repairs. Put a new tie-rod end on my Cadillac yesterday. Easy job. I can repair my car, even though it is much more complex and expensive than a camera, because the tools needed are things everyone owns (or should), like ratchets and sockets, screwdrivers, and wrenches. The large size of a car and its parts makes repairs actually very easy compared to working with tiny parts in a camera and very few parts on a car need assembled and adjusted to the kind of precision needed for a camera.
To really CLA a camera, you need specialized tools because many camera parts do not come off with a screwdriver, and forget about a socket and ratchet set! Once you've got it apart, you need specialized lubricants that, unlike car fluids, cannot be bought at Walmart or Autozone. You'll need a shutter tester that can read the speeds of both the opening and closing curtains. If you're adjusting a rangefinder, there are tools for that, too.
Leave it to the pros; you'll just f--k up the camera. Hell, I still had to pay a shop to do a wheel alignment on my car after I replaced that tierod end. Alignments on cars are one of the few common repairs that you simply cannot do yourself because of the specialized equipment required to measure the proper settings for the suspension and steering parts.