Before adjusting the truss rod, locate the plate with four screws at the bottom of the neck, situated at the back of the guitar body. Loosen the four screws about a turn, so that the pressure is removed from the backplate, but the screws barely leave their countersunk fittings. The back-plate should be loose from the body, but not able to move in any lateral direction. You might hear a few creaks as you do this. Next, re-tune the strings.
Normally, tightening the truss rod (clockwise, viewed from top for a top adjusting truss rod) will reduce the gap between string and fretboard (the neck arcs back). Conversely, loosening the neck (anti clockwise) will increase the gap between string and fretboard (the neck arcs forward). You’ll need an allen key to make this adjustment.
Put a capo on the first fret, then finger each string on the highest fret and check that it barely touches the frets in between the capo and your finger. If you play the upper part of each string (whilst still fingering the highest fret and with the capo still on the 1st fret) it should be playable with only a slight buzz. You may find that the lowest string (6) and the highest string (1) have different clearances to their respective frets. If this is the case, it might indicate a twisted (or otherwise distorted/warped) neck, which is difficult to fix at best. When checking the neck it is best to have new, or fairly new, strings fitted and always recheck clearances and tuning between adjustments.
Don’t forget to do a final re-tune and check, before moving on. Finally, re-tighten the back-plate screws to the same original tension (should be about a turn, if that’s how much you loosened them in the first place). Once you have set-up your neck, then you can go ahead and proceed with any bridge adjustments.
