I've only been working on watch movement for a couple of months, and am really enjoying it. Here's what I recommend to you do and have before you start.
1. Watch LOTS of Marks videos on youtube and get familiar with the Keyless work system BEFORE you start.
2. If you don't have a Loupe for you eye (3x or 3.5x )... buy one, they are cheap and needed. Also make sure you have good lighting.
3. Take LOTS of photos with a digital camera ... and I mean LOTS. Every step you do removing parts, document it with photos from it least 2 angles ... use the "Marco" setting on your camera if it has it.
4. Proceed slowly, carefully and gently.
5. Be confident, and enjoy the adventure :)