Thank you for the replies. I feel a bit nervous about cutting my SIM and I already cut the plastic teeth of my current SIM tray because I misunderstood another thread about this issue, so my current SIM tray is unusable. The trays that came with the replacement cases will not hold to my current case without wolke's modifications.

As for taking the chance with regular Torx tools, it's a gamble that works for some people but I'd also prefer to get proper tools, I already have regular Torx bits but I'm more worried about stripping the screws, and then what would I do?

I finally found, and ordered, Wiha Torx Plus 4IP and 5IP screwdrivers from MicroTools Europe. They should be here next week.