1. Go to the Track menu and select New...
2. Create a Stereo Instrument Track
3. Click on the first Insert Slot A then load UVI Workstation (stereo)
4. Activate the Record Enable button then select a preset in UVI Workstation and enjoy!
If UVI Workstation is not listed as a plug-in in Pro Tools, you can read the article UVI Workstation not Showing up in my DAW.