To perform this modification, you need, a T610 (obivously), a replacment fascia, a small flat bladed screw driver, and a T6 torx driver.
First remove the back cover, the battery and the SIM card.
Now remove the top part of the back cover (the part above the camera). Do this by inserting a small flat bladed screwdriver between the white and black parts of the phone, and lever the screwdriver up like a small crowbar on either side of the lens. The black cover should slide up and off the phone.
Looking at the top of the phone, remove the small on/off button and put it in safe place. Also remember to remove the little mirror or rubber grommit from beside the camera lens and put that in the same safe place as the on/off button. Losing these little bits will cause you no end of pain as they are not available as spare parts.
The next bit to remove is a small green plastic bit of circuit board. It's clipped in and sprung against some data pins. Again using the flat bladed screwdriver, pop it off in the direction of the top of the phone.
The whole rear of the phone should now be exposed. Using a T6 torx screwdriver, unscrew the four small screws indicated. Put these screws in that safe place.
Once the screws are out, hold the phone like so, and squeeze gently on the sides and lower edge of the phone case, the pressure should be enough to create a small gap between the fascia and the sides, using a fingernail or thin plastic (like a credit card) make the gap bigger until the fascia pops off. Repeat on the opposite side of the phone if required.
The fascia should now lift off completely, exposing the front of the phone.
Push your replacement fascia on until it clicks into place, and reassemble the phone. if all has gone well, you should have a T610 that looks as nice as the one shown above.