There pretty easy to take care of to tell you the truth. Just take care of it as you would any marker. Sit down, take it apart, and you'll realize there really isn't much to them at all. There are diagrams on AO, and i believe AGD's website still has them.
I would suggest getting a level 10 for it. I'm assuming since he quit 3-4 years ago that it's going to be a classic RT or RT Pro so it's bound not to have one on there.
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Sweet deal man, especially for free.
- Brian