Couple of ideas here if you want to try it yourself. It's not easy.
Brush the liquid adhesive around the edges of the tears and press them into the leather strip. Smooth out any rough surfaces with sandpaper, wipe the residue away with a wet cloth and dry the seat with a microfiber cloth. If there are gaps, fill them in with leather putty.
Leather Car Seat Repair: How To Fix And Prevent Tears And Cracks ...