Literally all you do is drag the kv.bin and cpukey.txt onto the root of your HDD and reboot. Once you turn your console on, it will shut off and then restart by itself. Then you're done. If it's not letting you put a new KV on then somethings wrong with your console.

First of all make sure the stealth server you are using allows KV swapping. also create a .bin version of the CPU.txt file which is part of the KV and use that.