What you need is only Brill's data files to make Gotagger to run. Here is the link:
http://kpl.hp.infoseek.co.jp/brilldat.htm
http://kpl.hp.infoseek.co.jp/brilldat.zip
You can also have GPoSTTL - Enhanced Brill's Tagger, at:
http://sourceforge.net/projects/gposttl/