There is a possibility in the KDE system-settings, but without using kde, I don't remember where to hangle through the menues.
Normally very close to the top, devices, ...

However, look at the /var/log/XF....0.log.
One of the first lines shows which config-file is used.
Most popular: /etc/X11/XF86Config-4

make a backup of that file, and edit it.
It's the best way to do it.