You actually don't need any special tools to open a screw on back. There should be special grooves on the back indicating that it's screw on instead of pop on. I use a pair of needle nose pliers ! Using the needle nose pliers straight up and down on top of the case,put the tips into the groves on either sides. Be careful to not scratch by slipping! U can use a thin peace of cloth over the back while doing this for a little protection. But that has always worked for me. Depending on how tight it's on May need quite a bit of force to break it free. I hope this helps ! Good luck ...