How to get the back off pantech reveal?

I have a new Pantech reveal phone. I was trying to switch sim cards. I don't have nails so I can't take them out and switch them. How do i get the back off the pantech reveal. I tried many things but it did not work for me. What in your views is the safest method to do that. I don't wanna mess up with the phone its brand new. Also there is a threat that the warrenty might go void. Please tell me how to take out the back panel. Earlier the storekeeper did that for me and I din't pay attention.