HTC Sensation

Remove the back cover

Turn the back of your phone towards you.
Press the back cover catch and remove it.

Remove the battery

Take hold of the the top of the battery and remove it.

Insert your SIM

Place your SIM in the SIM holder.
Slide your SIM into the SIM holder.

Insert battery

Place the battery in your phone (bottom first), matching the battery contacts with the phone contacts, and press the battery into place.

Replace the back cover

Place the top part of the back cover on your phone matching the phone with the back cover.
Press the back cover until it clicks into place.