Here's the how-to:
http://www.youtube.com/watch?v=tIiSaunTWWM
Don't be fooled by the 5 star rating "advanced". It is pure bullocks, and way easier than the Mini 2011/2012 which gets an easier rating by OWC.
The only tricky thing is the putty-knife thing, which is not tricky, it just demands some balls. You think you are breaking it, but you're not. It just feels rough to do, but it is quite easy.
You only need a sharp putty knife (not the thick plaster ones) and a philips P0 screwdriver. That's all. No weird gromets, pcb removal tools, torx screws, logic board moving etc.
Only thing to be aware of: the 3 antenna's have little gold plated connectors on the wifi logic board. These will usually stay in place, but have a look at them before you start to remove anything. If they pop loose, you might need to click them back in place, and that is easier if you know where they belong.
And take your shoes off, do it bare foot. Easier than all expensive anti-static measures.
If you can work clean in the kitchen, capable of nice handwriting, or good with the sewing machine, you can do this. Just demands a relaxed and proper handworking attitude.
And: consider doing RAM and drive at once. Upgrading now to 4GB, and to 8GB next year, and a new drive in between, is quite unnecessary. If you can afford to spend around 120$, grab 8GB and the Scorpio to have a maxed out machine ready for its next 4 years. The upgrade will add to its second hand value at least the money spend! A maxed out one can sell for 350-400$.