Here is a step-by-step rebuild with pictures:
http://www.skyimager.com/C14-rebuild.html
It's a C14, and the smaller sizes are the same, just smaller.
Remember:
focuser is disconnected first.
corrector is removed.
primary is removed
other mechanicals are taken apart.
You can soup up the SCT with a 2-speed replacement focuser from Feather Touch, fans in the rear cell, better grease in the inter-baffle space, and flocking the interior.
I've done several of them. It's really not as intimidating as you think. If you can collimate an SCT, you can take one apart.
You may not need to clean the mirrors, but everything else typically needs doing if the scope is older than ten years.