If you're talking about the white lettering in the knobs, it's pretty easy.
With a small brush, use some slightly off-white touch-up paint and fill in the lettering groves completely (even to the point where the paint goes outside the edges of the lettering).
After the paint completely dries, lightly buff the surface of the knob with a very fine steel wool. That will not only remove the paint that's not down inside the groves, but it will also shine up the face of the knob at the same time.
Works great on your shifter and t-case knobs as well.
I just did mine too. I taped off around the letters and hit them with some white spray paint. Peeled off the tape and rubbed off the excess with some thinner. I used too bright of a white, but it looks good.