could be done pretty easily, just unbolt the seats... and unplug airbag sensors etc. you could even remove the runners if you wanted, just make sure you bolt them down tight again,
not sure if unplugging the airbag plug would throw any fault codes up so you would have to get them cleared once back together,
as for somewhere to do it in Essex... wouldnt have a clue, im guessing it would be a do it at home on your drive kinda job or ask a professional detailer, who didnt mind taking the seats out, (or someone on here might be able to help if your not too handy with the tools...)