Remove the shower head from the end of the shower arm. To remove the shower head, rotate it counterclockwise and remove.
Pull the flange off of the wall and down the shower arm. Remove the flange.
Rotate the shower arm counterclockwise to unthread it from the copper piping in the wall. If the arm is difficult to remove, use pliers or an adjustable wrench to provide additional leverage. If you plan to reuse the shower arm, wrap it in a towel to avoid damaging it with the wrench or pliers.