First up, back up all your tracks (if you haven't already) on an external drive or perhaps several DVDs.
Personally, I'd buy a bunch of mailers and spend three nights getting the whole lot on ebay – register a creddly card and you can specify what time the listings are going to start – and ergo – finish. Perhaps a Wednesday evening, when folk are bored and sitting internetting? Spread the listings over a few weeks so you don't get snowed under and state in your listings that you post twice a week.
Lotta work, but better than sitting in front of the telly on cold, sleety, January nights…….