Look in C:\Program Files\Square Soft, Inc\Final Fantasy VII\data\ffprp for the 00.LGP and 01.LGP files.
Simply renaming those files can result in anomalies and you will not have all of the PRP models.
The Remix does a good job of installing the PRP models, but it still lacks a number of the newer field models.
Also, there are glitches with the model eyes and faces.
My team is working on a project that simplifies the installation of FF7 mods--
Bootleg Configurator.
Bootleg installs many mods including the field models from these artists and projects: Phoenix Rejuvenation Project, PRP ADDON, Dahfa, Squallff8, Bloodshot and Megaten. More importantly, Bootleg corrects quite a few glitches found in the original models: flickering faces, faded eyes and incompatibilities.
For a list of FF7 mods, check out the
Big List of FF7 Mods.
You'll still need to download the individual mods if you use Bootleg.