Worn out saddles are changed in a car service or equipped workshop by experienced personnel.
First, the seat is removed by drilling to a material thickness of 0.5 mm, and then it is pressed out. The hole unfolds under the saddle of the repair size. The new seat is pressed into the head heated to 250°C (hitting is prohibited).
It should be borne in mind that for each of the engine modifications, the repair dimensions of the seats are different, and when selecting them, be guided by the data in the catalog. After pressing, the seat is countersinked to fit the valve head.