The best way, and the safest, is just to save up some money and buy the full version. Nobody on here is going to know anything about cracking, or upgrading the sources of Map Tracker. Besides, if you really want to have a successfully tracked map, you
SHOULD NOT compile it yourself, with compiling it yourself, there would always be bugs in the items.xml of the sources, switch would mess up your map dramatically.. Besides, it's only $15.00 and if you want a good server, you should not be afraid to spend money.
Alternatively, you could probably get the 8.7 sources from a middle-man site, like the project hosting of Map Tracker on google, witch has all of the sources for every client they have. At the moment, I would probably just wait for the 8.7 Map Tracker to be released, and please, on OTLand, we will not tolerate any sort of things that are illegal, or try and crack any paid program. Anyways, the creator of Map Tracker is on OTLand and OTFans, why don't you try to contact him, and see what he has to say about the sources, or editing them.. Thats what I would do.
Thanks, Shalllow
Google Hosting of Map Tracker :
http://code.google.com/p/maptracker/