So again, that adjustable rod is between the brake booster and the master cylinder, you need to unbolt the master (usually no need to disconnect the lines), then pull the master forward about 2". you will see the rod from the booster that actually pushes the piston in the master cylinder. The adjustment is at the cylinder end of the rod.

The old ones (96 era) had a lock nut you loosened then turned the end into the shaft. The older rods were removable, I don't know if the newer ones are removable or not. The rod doesn't have to be removed to make the adjustment, but if it can be slid out, it makes it a bit easier. Again, a 1/4 turn is a lot of adjustment on that rod length, it doesn't seem like it would make any difference, but it does.