For those of you don't know what server-sided means.
Typically, a server is a software, such as a a gaming server, that runs on a remote server (Located in Seoul, Korea (Nexon EU, ME, and Asia), California (Nexon America), reachable from a user's local computer or workstation. Operations may be performed server-side because they require access to information or functionality that is not available on the client, or require typical behavior that is unreliable when it is done client-side.
Server side is the infromation that you need access to do this, sense you need to hack into the main servers in Seoul, Korea to get all kind of mumbojumbo shit, is it possible? In a way.. yeah but you'll have to be a whiz at computers, cracking, dodging the Korean government, quickly intercepting the mainframe and security protocols. You have to find the ports, bypass the ports sercurity and floods the servers, which cause it to overflow, forcing Nexon to 'shut it down' to fix it, while it it shut down, the secuirty is down and therefore you can worm your arse into it and find the coding (addresses) but then again, Nexon will repatch it quickly to fix it and all that hard work would be gone to waste AND the added extra security.
Also RPB, Client side hacking is also illegal, sense you're modifying the game without permission from the owner, in Nexon case, you're breaching their contract in the Term of Agreement which is also illegal.