Take the old bridge off and make sure when you put the new one on the original ground wire is under the new bridge when you set it in place to bolt it down,
You mite be thinking about when you change to vintage style pick-ups you need to use the copper ground that goes from the pick-ups to the bridge thats not the case here UNLESS its like that now(if it has the copper wire put it back where it came off of,that simple)so if its under the old bridge put it back under the new one.
goodluck
