Ye gods.
1) "If you are in the UK, by law, that kind of work in the kitchen may only be done or supervised by a 'Competent Person'. You may not DIY it."
That is untrue. You may DIY it, but you do have to notify LABC in advance if you're in England or Wales.
2) "rirst off,put a marette connector on each wire in the box. then move the metal box back into the wall a little further,securing it to the wall stud.then buy a blank cover and place it securely on the metal box using the socket screws.all should now be a little back from the wall, allowing you to plaster over the opening.you will feel secure when the power is back on."
Miner - I have no idea if you're in the UK or not, but from your use of the term "marette connector" I would guess not, or if you are then your background is non-UK.
What you suggest is likely to contravene the wiring regulations because of the rules on concealed cables, and therefore likely to be illegal.
Please don't give advice when you are not competent to do so, particularly when, as in this case, it could get someone killed.
Concerned of London, August 2009