Car Upholstery: Broken seat cushion on 2000 SEAT Alhambra SE 115 Tdi, torx screws, proper density

Question
The drivers seat foam cushion edge nearest door has collapsed due to frequent use.  What is the best way to go about repairing the seat.  It is fitted with side air bags and heating elements. Are any special tools required to change the foam cushion and cover?  

Answer
I am not familiar with attached airbags or this make or model. Always use extreme caution. Static electricity can set them off. Disconnect power to seat. Wear nonstatic clothing. Do not work on a carpeted floor. The heating elements are usually in the center foam section. Remove seat and separate. Shape proper density foam to be sectioned. Cut old foam out. Glue new foam in.Replace cover. Reassemble and install seat. Tools required:Depending on make and model generally include sockets, rachet,screwdrivers,hogring pliers, and pliers to pull out old hogrings. Some use allen or torx screws also, depending on each indivigual vehicle. Mark.