Fixing large hole in plaster

We've got a hole in the plaster which is about 80mm x 160mm. On the left of the hole is the window frame and on the right is the electrical switch for the electric shutter. Ive never fixed a hole in a plaster so I need some advice on how to tackle it. Can someone direct me to a site which explains how to repair it? Because when I googled a lot of the sites didnt have pictures and sicne its my first time I'd prefer pictures.

Here's where to hole is.


http://img261.imageshack.us/img261/8...e238yx7.th.jpg


Thanks


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