I left the display attached. I made a stage for the phone using the Amazon box the phone shipped in. Cut off most of four sides of the box, leaving the bottom and one end. Left enough of two sides to keep the end upright, Then I set the phone in my stage, taped the display at 90° to the upright box end, and proceeded with the replacement. No issues. Maybe helpful hint: Make sure you know exactly how to place the new battery before applying the adhesive. If you stick it in too high, you won't get the cable connected. I needed to form my cable to get it plugged in and was glad I did a trial run before sticking everything in place.