Normally the cord for the mute button is about 4 feet long.  Figure out where you would like to mount your mute button.  The flat mute button has strong mounting tape on the back side of it.  Mounting on a smooth surface would be ideal. 

Clean the surface with rubbing alcohol or some sort of cleaning agent.  Let the surface dry, peel the backing off of the mounting tap and apply pressure for a few seconds so the mounting tape will adhere well.

Normally the cord for the mute button is about 4 feet long.  Figure out where you would like to mount your mute button.  The round mute button needs a hole that is approximately 1/4" or 6.5mm to mount.  Try to test drill a hole onto an extra piece of plastic or wood that is not needed to make sure the hole is sufficient.

Make sure the chosen mounting location is either 1/8" or 2.5mm thickness or less.  Round mute button will not screw into a hole if the mounting surface is any thicker.

Unscrew the nut from the round mute button.  Place the round mute button through the hole from behind with the lock washer on it or after the mounting hole.  The lock washer is the round washer with the slit in it, it is slightly curved up from each end.  The lock washer is needed so the nut will not loosen from vibration.  Hold the round mute button with one hand and hand tighten the nut onto the round mute button on the front side of the mounting hole.  Finally tighten with a pair of needle nose pliers just until the lock washer flattens.