There isn't a whole lot of work involved. Basically you need to wire up power, audio, and a video board, i.e. the Neobitz Component/SVideo board from
www.neobitz.com works great
You start by planning out your power switch/socket and a/v jacks and drill all necessary holes. If you decide to paint the shell, prep, prime, and paint after drilling.
The best way for planning locations is to take some painter's masking tape (easy peel stuff) and put it along the back edge. Measure drill points to properly and evenly space the jacks. You won't want to mount anything behind the cart slots as it will be painfully visible and could obstruct the cart slots.
Once you have the shell ready, all that is left is mounting the jacks and wiring. You'll need to be familiar with using a soldering iron. You won't need to be an expert but a novice could have a rough start -- but I think anyone could get through it.
If you need to see pics, I took some of a 2-slot I just consolized for someone. Thankfully, I didn't have to do the painting so it was a quick and easy job.
Jeff