How to remove the fixing screw of Audi a4l valve cover when it slips?

1. First, fix the engine on the revolving frame and put the revolving frame on the workbench.

2. Secondly, remove the valve cover, remove the oil reflector on the cylinder head, loosen the cylinder head bolts, and remove all the cylinder head bolts in the way of first two sides and then the middle.

3. Then tap the joint between the cylinder head and the cylinder block with a soft hammer to loosen it and remove the cylinder head. The cylinder is a cylindrical metal part, which guides the piston to do linear reciprocating motion in the cylinder. It consists of a cylinder, an end cover, a piston, a piston rod and a sealing element.