Stilo Air bag system passenger OCS replacement

Undo the 3 electrical connectors under the seat front. One orange (side airbag), one white (seat belt on or off sensor) and the OCS sensor one which is grey.

The connectors swing out for easy access on a tray by unfastening a plastic push clip. Move the seat fully forward and undo the two allen key seat rear securing bolts. You’ll need an extension tube for leverage if you’re just using allen keys. Then slide the seat fully back and remove the front two seat mounting allen bolts

You don’t need to remove the seat entirely out from the car, just carefully manoeuvre the seat base so it’s facing out the door.

You only need to move the seat cover back far enough for access to the bottom seat cushion in order to replace it. The cover is held in place by a corded band which is hooked over the seat metal frame in various places around its circumference and by two eye hooks at each end.
To gain access to the hook locations you need to partially release (but not totally remove) the seat plastic side covers. For the door side panel there are two screws at the rear and two at the front of the seat to remove, then you can lever the panel far enough away to gain access to the seat cover hooks
Unclip the two hooks at each end of the seat cover cord with a pair of pliers and working around, unhook the seat cover from the various securing frame hook locations. You’ll need to remove the under seat tray completely for access to the central front hook.

For more access you can release the seat rear cloth flap which is a couple of rubber bands with hooks on the end, attached to the seat base centre.