After the neck on my Mustang Bass RI "settled in" following replacement of the factory rounds with heavier flats, it became obvious that a truss rod tweak was in order. This was my first time adjusting a truss rod from the body end of the neck, so I thought I'd pass on what I learned from the experience.
First off, if your neck pocket is a nice, tight fit (as mine is), BE CAREFUL when you remove the neck. Be sure you lift the neck straight up out of the pocket without applying any side load or you may crack the body finish around the neck pocket. Fortunately, this notion occurred to me as I was removing the neck, so I proceeded with care and perpetrated no damage. Obviously, similar care must be exercised when returning the neck to the pocket once the truss rod adjustment is accomplished.
Second, I had intended to use an offset phillips screwdriver (see chrome item in PICs below) but neither end fit well into the business end of the truss rod and the LAST thing I wanted to do was bugger up the truss rod with an ill-fitting bit. So I chose a perfect-fitting slotted driver bit from my collection and used it in my blue, Makita, driver handle (also pictured). Note that this handle has a red, fold-out "wing", the use of which provides better leverage than a plain driver handle would.
A final suggestion: when screwing the neck back on, make sure everything is properly aligned and then turn the screws back in BY HAND. I removed mine with a battery-powered drill/driver but didn't want to chance over-torquing the screws and thereby stripping out the screw holes in the body when I put the neck back on.
Tightened the truss rod just a 1/4 turn (which took the excess relief out of the neck) and lowered the bridge saddles a hair and voila: she's playin' much better!
I'm sure this stuff is old news to most of you, but I posted it in the hope that somebody else as inexperienced as myself might benefit thereby.