How do I replace the latch on a Trionic Walker?

How to best replace the latch on a Trionic Walker Rollator folding mechanism.

1. Open the keyring with a small screwdriver.
   
   
   
   
2. Remove the red strap from the keyring.
   
   
   
   
3. Remove the keyring from the pinhole.
   
   
   
   
4. Remove the pin and spring.
   
   
   
   
5. Unscrew the nut with a 4 mm Allen key and a 10 mm spanner.
   
   
   
   
6. Remove the nut and the spring washer.
   
   
   
   
7. Remove the latch (locking mechanism) and make sure that the small tubular spacer is still positioned on the screw.
   
   
   
   
8. Attach the new replacement latch.
   
   
   
   
9. Assemble all parts in reverse order according to points 6–1 above.