Louis,
Firstly have you installed the update-system rpm?
If yes then:
use that to uninstall the rpm
If no then:
Do you know how to get a command prompt?
If yes then:
type this at the command prompt:
rpm -e {name of rpm without the numbers}
for example if I wanted to uninstall e-smith-fubar-1.0.3-3.rpm then I would type:
rpm -e e-smith-fubar
Other than those 2 ways I do not know of any other way to uninstall it

Cyrus Bharda