_RefLevel, change the bigint value to it's maximum where you meet the lever you want to set as max.
Hex edit SRO_Client.exe as well as SR_GameServer.exe
You can find guides for the HEX editing in the release section or you could use the epvp's search function.
In case you fail using the epvp's search function, head to google.com (or whichever your "home" google is) and write "Assembly guides vSRO site:elitepvpers.com"
In case you are clueless on how to use google :