Some back boxes have holes in the back behind the screw connector, but if your's hasn't drill one with a suitable size drill. Get a long machine screw (50mm should be enough if you've a 25mm back box) and then the screw will bite into your new screwhole. Probably a good idea to turn off the power while you've got the socket open and the wires exposed when you've got a drill in there ....
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local