well there are a couple of options,you can change string gauge like the other cat said,or you can go buy another spring and cut in half or 3/4 or whatever size you need, and you did'nt mention the make of bass so i'll tell you this anyway, older fenders came with a longer g adjustment screw and spring for this exact purpose,you can shop around for the longer(or shoter ) type screws to fit your need,what string was it? or is it all of them? if you cant fix it on your own bring it to a pro, but these suggestions should do the trick
