Print the button with whatever nozzle size you like, I did have to drop down to a .4 for the top piece of the cable guide and use a brim. 

I printed mine with Prusament Pro Green PETG. 

The bottom has a hole for a small zip tie, the top fits on the sharp notch on the power supply lid and when closed keeps everything from moving.

Edit: flip the bottom piece upside down, and stand the top on the two legs, I am not exporting the files again.