The HTC P3600 Trinity is a really great phone. But opening the back to put in the SIM and battery is really astonishingly difficult.
The first piece of advice I offer is if you bought the phone in a local store, go back and have a member of their staff do it! Even if it is a long drive! If it does break then they will be responsible!
But, like many people, I bought mine from an online merchant so that was not an option for me.
I regret it is difficult to provide a meaningful photo. But I hope the following description may be helpful to someone.
Ignore the very minimal directions in the user guide which simply refer to sliding the back open. This is misleading. No sliding is involved. The photo in the user guide also does not correspond to the actual back of the phone so should also be ignored. It is actually one piece of molded plastic that encompasses the entire back and goes around some of the sides too. There is no panel or section to slide or swivel open.
Also ignore the two little raised bumps low down at the back. They look like the back of the Magician. I initially expected to push downwards on them to slide the back off. Not so!
Unlike the Wizard there is no release switch, as there is no panel to open.
The back pops completely off by being levered directly backwards away from the front of the phone. Not up-down-left or right. Just directly backwards.
|Back| <--> [Prise with force!] <--> |Front|
I recommend using a soft surface for your phone during this ordeal! Something like a big cushion or a sofa or a bed. Not a hard desk. This process will take both hands and your phone will need a soft landing if slips away from you!
The only notch to use for initial leverage is if you remove the stylus. I took out the stylus to make this notch accessible. I then used two spare Magician stylii to prise the back off. I used the handle ends, not the tips. First I placed the handle end of one stylus in the notch where the Trinity stylus goes and twisted it very hard to begin to lever the back open. Once a gap began to appear I forced the handle end of my other spare Magician stylus into the gap to hold it open. Then I found another gap to prise another place on the back open more.
By using the two stylii handles with considerable force I was able to work around the back of the phone until it popped off with a loud "clack". This was an uneasy and contradictory combination of force and care!
Fortunately, I managed to do this without damaging or denting any part of the phone. I was quite relieved as it was not easy.
It does seem the back is made of strong plastic which is sufficiently strong and flexible to stand this force!