Photo Credit: Courtesy of 3DStockPhoto ( image)
Write a few pieces of gcode to do this. Place it on an SD-card (I assume you have a reader) and select the file you want to execute.
G28 G1 Z0
Do you really want to home it directly? I would say you want to take it down slowly and adjusting end-stops incrementally.
G28 G1 Z10
G28 G1 Z3
G28 G1 Z1
You can also move it around in the X and Y plane:
G28 G1 Z5 X50 Y30