Take the cap off of the top of the tower. You will expose the shank behind the faucet. You may have to loosen the nut in order to spin the fitting up towards you to access. Or simply take the nut off an slide everything out of the front of the tower. Be certain to reverse this when you put everything back together.
As to line length and pressure, never adjust pressure based on the length of line. Pressure to keg is always determined by beer temperature and carbonation level. What brand of beer are you dispensing?
Scott Zuhse, Instructor
Micro Matic Dispense Institute