I personally wouldn't glue all the carpets down just in case you need to lift them in the future (small bits of welding?)
Remove front seats.
Remove the sill covers. Take the long strips of carpet for the sill and trial fit them (they are usually too long). Once the right length I glue these using something like Timebond which allows you to reposition them to a perfect fit. Leave to dry. I then fit the wheel arch cover which I also glue to save it falling down. Refit the sill covers. The next bit is the piece of carpet that tucks under the back seat and falls to the floor either side of the transmission tunnel. I remove the lower section of the rear seat to make this easier)This may need a bit of trimming to make it fit the tunnel. It has a vinyl edge which tucks under the rear seat. I glue the vinyl to the front metal lip edge of the rear seat floor. I use clothes pegs to hold it in place whilst it dries
Next fit the gear lever cover (the black metal cover then goes over this and is screwed to the floor) and handbrake carpet cover. Lastly the large 2 sections of rear carpet and then the 2 front sections which overlap them a bit. Carefully mark the holes where the front seats will be bolted to the floor. A meat skewer/bradawl will do this. Bolt seats to floor tightly and replace rear seat
Hope this helps!
