Fitting Aerial Socket

[Zambezi]

These are probably the most widely available and the cheapest.
http://www.screwfix.com/prods/81956...her-Plasterboard-Plug-LDF-4mm-8ga-Pack-of-100
Drill a hole through the plasterboard (it tells you what size drill bit to use on the pack), push one of these plugs into the hole, line the hole in the back of the surface box up with the hole in the plug, insert screw and tighten, repeat for the other holes.

 

[boomtheroom]

sorry i mean the backing of the surface mount ie..the part that goes in behind the plasterboard

 

[Zambezi]

Surface mount = box sits on the surface of the wall (using the fixings I linked to)
Flush mount = box is recessed into the wall (using something like this http://www.screwfix.com/prods/44827...x;jsessionid=LMGRNKMDQJJ2UCSTHZOSFFY?ts=13210

 

[boomtheroom]

yea thats the one flush mount....how do u retain the back bit in the wall does it have to be installed near a wall studd?

 

[Zambezi]

No ideally they should be installed a little way from the studs because they have little "tags" (yellow bits on the side of the one in the link I posted) that protrude out the sides of the box once it is in the wall, which tighten up against the wall when you fit the face place.

Mark a square the same size as the back of the box I linked to, use a pad saw to cut out the square (run the pad saw on or just over the line to give you a little bit of play, otherwise the box will be very tight), feed the cable/coax through the back of the box, then push the box into the hole in the wall, push/snap the little side tags into the holes in the sides of the box, connect up the cable to the face plate, fit the face plate onto the back box with the screws provided, as you tighten the screws the tags will tighten onto the plasterboard, clamping it in place.