Hi
I installed Nagios via YUM on centOS but im unable to change the front end.
does anyone have a guide or any advice
first drop the RPMs and resintall from source, at that point follow the instructions in the frontends donwloads 
nagios.org/download/frontends
Problem is the RPMs change the folder structure of nagios on which the frontends base…
If not you may want to wait for somebody who has nagios installed from RPM on RH/CentOS and see if (s)he can help you.