The zero fret is a unique feature of the RS guitar.
It serves as a frictionless "nut" for the tremolo system but also gauges the height of the strings at the low end of the neck.
There is little or no need to interfere with the zero fret. It will naturally wear with continued use of the tremolo. You will notice indents appearing (under each string) that will cause the strings to "click" or "ping" after a time. This is normal and does not interfere with normal playing.
Excessive wear will eventually create fret buzz on the lower frets and even choking.
The zero fret may then require replacing.
It is advisable to have this kind of work carried out by a professional unless you are conversant with fret removal, replacing and dressing.