Just download IMGTool 2,
1. go to ... \Program Files\Rockstar Games\Grand Theft Auto Vice City\Models
2. In gta3.img and gta3.dir options uncheck Only For Read!
3. Open GTA3.IMG with IMGTool
a) Find dts_shops1.txd, remove it, (DEL button) and Confirm
b) Find dowbikershop.dff, remove it
c) Add new unpacked files (CTRL+A) dts_shops1.txd dowbikershop.dff from archive
d) Rebuild Archive (Commands\Rebuild Archive)
PLAY THE GAME!