My old fender p bass seems to need a tune up of sorts. I'm wanting to lower the action a little. I've lowered the saddle or those string holder things all the way they can go, but they seem to still be too high. I was wondering if I should attempt adjusting the neck or if it would be a better idea for me to bring it in to have it done by someone who might know what they are doing. I've never done this before. Thanks.