That guy is full of sh!t. The rebuild kits can be had for about $100, and any shop that services racing bikes, quads or snow machines can recharge it with nitrogen in about 15 minutes for about 20 bucks.
About all you do on a rebuild is take it apart, clean the guts and put it back together with a new shaft seal and a couple o-rings.
Your buddy who wrote the note wouldn't happen to have a nice new shock to sell you, now would he?