Download all files (GWX3-1.bin,GWX3-2.bin,...,GWX3-7.bin and GWX3.exe, everything should weight 1.31GB) and run exe file. Before intaling GWX make sure that your SH3 is ver. 1.4b otherwise patch it:
http://www.subsim.com/radioroom/down...do=file&id=158