1. Carefully remove the piston rings through the piston crown, being careful not to scratch the aluminum alloy. Do not try to remove the rings through the piston skirt, because. they are iron and break easily. To facilitate the removal of the rings and so that they do not fall into empty grooves, thin steel plates or feeler gauges can be placed under the rings.
2. To insert the probe, lift one end of the ring to be removed from the groove and insert the probe under it.
3. Slowly guide the feeler gauge around the piston, at the same time slightly lift it so that the ring comes out of its groove. When the ring rests on the flat surface of the piston next to the groove, remove it through the bottom.