How can I adjust the truss rod on my guitar to tighten or loosen it?

To adjust the truss rod on your guitar to tighten or loosen it, locate the truss rod adjustment nut usually at the headstock of the guitar. Use an appropriate tool, like an Allen wrench, to turn the nut clockwise to tighten the rod and counter-clockwise to loosen it. Make small adjustments and check the neck relief to ensure proper alignment.