How to get my sim in my iphone?

Just wanna know how to get my sim in my iphone been trying since this morning can anyone help me can't get the bck off the phone x

I assume you mean a sim card slot.
The iPhone 5 takes the smaller SIM card, known as the Nano. You will want a small paper clip to open the SIM Tray on the right hand side of the phone.

Hi if its an iphone 3 the slot is up the top, if you look you will see a little hole about the size of a needle, push a pin into it and the sim tray will come out, on the 4 and side its on your right side of your phone