I have a seat back that continually falls off, so hope that this helps you remove yours. Down at the base ( just under the seat back) are two push lock fasteners that push up vertically to lock. At either side of the seat back (about 2/3rds up from memory) located on its front face and therefore hidden from view, are two unusual shaped clips that lock inside the rear of the actual seat. My guess is its these squeaking. As I have never had to pull them out (bloody thing falls off after a few hours of driving) I am not sure just how these clips release. If you struggle to release them let me know and I will take a couple of photos. Good luck