[CentOS] How to import/install the key for signing pxljr-1.1-1.i386.rpm

Tue Nov 27 21:03:49 UTC 2007
Andrew Allen <andy.allen at virgin.net>

How do I import and install the key for signing the above rpm (driver
for HP Colour laserjet 3500 printer) which I've downloaded from the kde
repo? - I want to use yum localinstall, but when I do I get the message
'package not signed'.

Thanks for help,
Andy