Here is a guide for changing the housing on a Sony Ericsson K750i. It may seem like a difficult job but actually it's very easy to do. You will need a Torx T6 screwdriver and a very small Philips screwdriver. The Torx is a specialist screwdriver that you can get from us - the other being a common one featured in most domestic tool kits. Chances are you might have one already.

1) Remove battery, and sim card from the phone and remove the back battery cover.

2) The immediate screws to undo now are the two standard ones - these are located top left and top right of where the battery cover should have been - easy to spot. The others are the Torx ones in the bottom corners. Keep the screws safe.

3) With the screws undone, the back cover can be removed. This can be done with a plastic shim or other implement. Apply a bit of leverage and it should become free.

4) Turn the phone onto the front, and use the same procedure for the front housing.

5) Fitting the new housing is just a reverse of these steps. If you have a chassis with the housing, you can also transfer the board of the phone in the new chassis before reversing the process.