Attention: mark the parts so that they can be put back in their old places, do not mix up parts from different sets.
1. Remove the spark plugs.
2. Using a valve spring compressor, compress the spring.
3. Remove the breadcrumbs (225).
4. Remove the valve spring retainer (224).
5. Remove the valve spring (223).
6. Remove the valves (228).
7. Remove the oil seal (222), which is also the lower spring seat.
8. If necessary, remove the process plugs (216) of the cooling jacket.
9. Unscrew the coolant temperature sensor (725) (left half block head).
10. Unscrew the plug (229) (right half block head).
