Bashing the wrench with a mallet may work but it is a bit harsh on lightweight qeuipment.
I use some gentle foot force on a long wrench.
Place chain in lowest gear.
Position the non-drive crank forward/up at 10:00
Apply the wrench rear-up at 2:00.
Apply both brakes.
Put foot onto wrench and tranfer weight. Bounch up and down with care.