If you have two people it’s pretty easy. One person lifts, the other person screws whichever leveler you’re adjusting up or down a couple turns. the lifting person drops it and checks the level.
When I’m on my own I do basically the same thing. Lift with one hand, turn the wrench 360 degrees, drop the machine, check the level. You can also just turn the levelers without lifting the machine at all.
I think perhaps the distinction is using a wrench even if the levelers are free enough to move without one. It helps you keep track of how many turns you’ve done. It’s also an easy way to adjust the slope when the machine is already level. Just do the same number of turns on the right and left side. If you’re just turning the levelers without keeping track of how much they’re turning it’s pretty much just guess and check… and guess again.