You don't. The only solution to damaged piston rings is to take the engine block out of the car and replace the rings.
The piston rings create a seal between the piston and the cylinder wall.
Loose or damaged oil drain plug; Plugged or damaged pcv valve; Worn or broken piston rings.
One or more of your cylinders are not holding their seal. Worn out piston rings, worn/damaged piston, worn/damaged cylinder wall are the most likely problem areas.
Gently, they break easily. They also make tools to R&R piston rings to avoid breaking the rings.
Oil rings Combustion rings Piston rod Piston rop cap
The piston rings are fitted round the piston to make a better gas-tight fit in the cylinder.
Piston rings and/or (probably and) cylinder walls are damaged. Rebuild the engine.
Running an engine with broken piston rings will cause damaging scoring in the piston chamber, and is not to be recommended.
It is a spring metal sleeve that goes over a piston to compress the rings so that the piston can be install in the motor. It tightens down on the piston, forcing the rings into the grooves in the piston then you tap it into the cylinder.
Worn piston rings, bad valve seals,
The purpose of a piston ring expander is to make it easier remove and install piston rings. Because of the low torque they use, they help to prevent damage to the piston rings.