Now you're going to adjust the pick-up height on your bass guitar. Largely, this is a matter of personal preference. Some people like it really close to the string for a much louder tone. Some people like the hollow sound of having the pick up a little further away. A good way to start is to take a measurement going from the pole on the top of the pick-up to the bottom of the string. You want it to be about six or seven 64ths from the pole to the bottom of the string itself.
With a Fender bass you can do the outside strings first. Same thing there, probably about four to five 64ths away. Then you can actually just visually kind of match the radius of the neck which is the same as the bridge at this point. You're going to raise or lower depending on what it looks like. This is not an exact match of the radius, it just kind of needs to look the same as the bridge. Then you want to actually plug it in and play it and see how it sounds. That's how you adjust the pick-up height on a bass guitar.