Download and extract the files. If you're downloading the default replacement versions, Backup your existing files first, though. Make sure that you have moved the original templates somewhere other before you put mine. Don't replace/merge any existing files!
Default Replacement Versions:
Cut and paste G001 to
C:\Program Files (x86)\EA GAMES\The Sims 2 Seasons\TSData\Res\UserData\Neighborhoods
Documents\EA GAMES\The Sims 2\Neighborhoods
Note: If you have The Sims 2 Ultimate Collection, cut and paste it here instead.
C:\Program Files (x86)\Origin Games\The Sims 2 Ultimate Collection\Seasons\TSData\Res\UserData\Neighborhoods