It's pretty easy.
Just go into your GTA3.IMG and extract "glock.dff" and "glock.txd". Import "glock.dff" into ZModeler, and click File -> Merge and open your Glock. Now line it up and scale it to the original Glock, take note of the object name, then delete the original Glock object and rename your new Glock to the old one. Then you can simply export to .DFF and load into Vice like a regular weapon.
Scott:Okay, Houston. As I stand out here in the wonders of the unknown at Hadley, I sort of realize there's a fundamental truth to our nature. Man
must explore.