[Xymon] Proper method to upgrade

I have Xymon 4.3.11 installed and would like to move to 4.3.15, but I do not see any upgrade doc. What is the proper method to do an upgrade from source ?

Do I uninstall the previous and install the new version? Should I just install the new over the old version, using the same config options ?

Best practices would be appreciated, since this is a Production environment.  Centos 5.4 64 bit.

Thanks !

Michael