Replacement should be carried out with the rear bumper removed, assemblies and parts that impede the performance of work.
Drill out resistance welding points with mating parts: sidewalls, rear wheel arches and floor panel. Straighten and clean the deformed edges of the body. Install a new rear panel with a rear cross member on the body, fit to the mating parts and fasten with pliers. Check the installation of the panel for gaps with the tailgate. By welding in a carbon dioxide environment, the panel is fixed at 6-8 points with wire Sv-08G1S or Sv-08G2S with a diameter of 0.8 mm. You can use gas welding with solder L 63, L 68 or LNKMts in the form of rods with a diameter of 2-3 mm.
Weld the rear panel with the cross member assembly to the mating parts through pre-drilled holes. Hole diameter 5-6 mm. They clean the external welding seams flush with the base metal and perform painting work and anti-corrosion treatment of the repaired sections of the body.
Install the bumper and the removed components and parts in the luggage compartment and outside the car.