Change headers name


I’d like to change in the ‘RT at a glance’ page the ‘RTFM’ header text by
something else (more relevant) like ‘Knowledge Base’.
Anyway I’d a look in the doc and hesitate after findind several places in
the code with ‘RTFM’.
My question is where do I have to change that , in
/opt/rt3/share/html/RTFM/Elements or /opt/rt3/share/html/RT/Elements and
in which Elements (Tabs or Header).
I know that to change something I fuirst need to copy the file in a local
Thanks for any reply.