Where can i find a runescape stat changer that works?

All RS stat changers and other editors like that are all fake. They're most likely keyloggers or contain trojans or other viruses. The fact is that RS stores all characters in their servers and you can't do anything to change your character's stats because that would involve nothing less than hacking the RS servers. Your best bet would be either to give up trying to cirvent the grind or grab a macro.