Here's an easy truss rod adjustment technique: take the leftover bit from string #1 and use it as a feeler gauge. Capo the first fret, fret string #6 at the last fret and slip the "feeler gauge" from #1 between string #6 and the 7th fret wire. Easy peasy after that; tighten the truss rod to reduce the neck relief or loosen to increase the relief using your new feeler gauge.
Bonus: makes it easy to check the neck when changing string gauges
