Your refrigerator can be raised or lowered by turning the adjustable leveling feet clockwise or anticlockwise (as shown by the arrow) if your refrigerator is not level or is on an uneven floor.
Normally the front two feet can be adjusted. Leveling left to right or front to hindside, you can adjust these two feet. But the two feet of the back can't be adjusted.
Almost all the feet can be adjusted by hands. When the refrigerator is put to the place you need. Use you hand turn the feet,when the refrigerator is on even, it is ok. If there are two wheels in the front of the refrigerator. You don't adjust the feet too high. It is best to let both of feet and wheels support the refrigerator.
If the foot is too tight, you can use the flat screwdriver to adjust it.