ive got an esp bass with two emg pick ups. one of the knobs got smashed in and now it cuts off so i have to replace it. its a double stack 250k. at least thats what i can gather on the net. can i get a new one and put it in myself? does it have to be a 250k or can it be 500k? its monday morning and i have to have this done by tomo night to go on tour. uh..