Easy Install:
Copy the "VRT3" folder into the modloader folder.

Manual install:
Replace all files from the "textures" and "palm" folder inside the gta3.img file and copy the models folder into the game folder and press replace.
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Side note:
I always loved the look of the SRT3 mod for San Andreas, so I figured out it might also need a Vice City port with making it fit for the Vice City universe. I used resources from the Gostown Paradise project, nothing from the SRT3 project was actually used.

Huge thanks to the SA Gostown Paradise project. - VC converted without the extra assets.