Well RTM in general is for DEX only,
RTM: Real Time Modding
But to RTE its through CCAPI for CEX and DEX,
RTE: Real Time Editing
Its really simple to setup and do for CCAPI method, TMAPI method requires wired connection from OC to Console.
If doing CCAPI method, you best make sure its installed and up to date with your PS3's CFW support.