You can remove Passport Photo Workshop like any other Windows program. Follow these steps:

Windows XP
Close all Passport Photo Workshop windows.
Go to the Start menu > Control Panel.
Click Add or Remove Programs.
Double-click Passport Photo Workshop.

Windows Vista / Windows 7 / Windows 8 / Windows 10
Close all Passport Photo Workshop windows.
Go to the Start menu > Control Panel.
Click Programs and Features.
Double-click Passport Photo Workshop.