The tool needed for this adjustment is a 1/4″ ‘nut driver’ wrench available at any hardware store such as Ace. They used to be small enough to fit, but recently many driver brands seem a little too large and some grinding on the outside diameter may be necessary. The luthier supplier Stewart MacDonald www.stewmac.com 800-848-2273, has a 1/4″ thin-wall truss rod wrench that will fit as well. A small, tight fitting Phillips screwdriver for the truss rod cover screw is also important so that you don’t cam out and damage the screw head, or scratch your peghead.
You can find more information and recommendations regarding action height adjustments on our Guitar Care page. Please be sure that you are knowledgable in guitar repair and action adjustment before attempting to adjust the truss rod yourself. If in doubt, seek assistance from a professional.