Instructions
Download RiceVideo Plugin and the .zip file of the texture pack for the game you want to use. Unzip RiceVideo Plugin to the "Plugin" folder of the Project 64 installation folder.
Open the "Plugin" folder in the Project 64 installation directory; then create a new folder, and name it "hires_texture." Extract the texture pack zip file to this folder.
Open Project 64, with "Rice's Video Plugin" selected as the video plugin. Go to the "Options" menu. Select "Configure Graphics Plugin;" then click "Texture Filters." Check the box that says "Load All Hi-Res Textures If Available;" then click "OK." Load the ROM that you have downloaded a texture pack for, and a prompt should appear informing you that the textures are loading. When this process is complete, the game will load.