EvilJohn said:
Disconnect the pretensioners that are already attched to your old seats, no need to cut the wires, then put you new seats in and put the old pretensioners in.
Thats a pic of the pretensioner mate.
Heres a wee guide just for you and only about the pretensioners, not the whole interior.
Step 1 Disconnect battery
Step 2 Wait 10 minutes, have a cuppa or a w**k or whatever
Step 3 Take off the plastic that covers the pretensioner, you need a t20 torx screw for that.
Step 4 Unbolt that 1 big screw you can see in the pic above, about t45 torx.
Step 5 Take the wiring off the bottom of the seat
and disconnect one side of the wire from the other.
Step 6 pull wiring through the gap at the side of the seat
Step 7 You have now removed your pretensioner
Refitting is the opposite of putting it in, its not difficult mate, give it a bash and it'll me all good.