Typically pretty easy. Many compactors are sourced from the same mfg. Disconnect electrical source. Pull the compactor out and gently lay on its side. Remove the bottom panel and you will see a large drive gear (mine's plastic) that may be broken and the cause of your problems.

In any event you can turn that gear to move the ram. You will likely need a sock wrench to turn the nut in the center of the gear as it may be very difficult to turn by hand. Turn the gear counter clockwise to raise it. If the gear is broken parts are relatively inexpensive and easy to replace.