it is really easy.. if you remove the seats (bolts through the rubber grommit covered holed through the floorpans inderneath the seats) and the carpet you see two boxes spot welded on to the floorpan. you simply cut the boxes off the floorpan and move them 2 inches rearward and welt back in, ( you can aslo cut some material off the front and rear lip facing the floorpan to lower the box) re drill the holes to access the seat fastening bolts (cover the old ones) and reinstall in the reverse order you removed it in...
link to article with pictures...