Quoted from Rascal_H:While on your hands and knees under your pinball machine use your back to lift the machine... then use one hand to spin the feet around a few times. Lower the machine and scoot out from under the machine. Check the level on the playfield to see that it's still wrong. Repeat as necessary. If done correctly you will eventually have a level pinball machine and a sore back.
That's my method too.