Fronts are a piece of piss, straight in they go. The backs will go in quite easily without any major welding. The bases just pop into the seat well, the front clips into existing holes, the centre bolster fits in snuggly. The major thing you need to do for the back is make extended bolts for the backrests to clip onto the sides. You can get all you need from B&Q, basically that is two extra long bolts (think they are 8mm, take your existing bolt out for comparison) and a length of aluminium tubing to hide th bolt (I used a black marker to hide the shineyness of the alu) Here are some pics, you can see the aluminium leaning by the front passenger seat. You can start drilling holes and trying to secure the back rests at the bottom, however, I reckon its not necessary as when passengers are seated in them they will not go anywhere as long they strapped in.
If you have yet to get your seats, try and get later VR6 spec seats like mine, they are nicer material and are more supportive and 'bucket' like. I got mine for ?100 and that included the rado leather steering wheel as well
