depends, some are executables and you just run them and some you replace the orginal exe with the patch. read the instructions of the download page for what to do - it'll tell you there.
Canadian? Sign the petition. Let Ottawa know you want to be considered and that you don't want your rights to be abraded every time the music industry's profits slip a little.
how do i apply the official splinter cell 1.2 patch, then Replace the original SPLINTERCELL.EXE & CORE.DLL executables with the ones from the File Archive