if they are still like the old orderpickers and from what i can see in some of the pic's of these units i've looked at they are.
you need to raise the platform slightly to allow better access to the out rigger legs where the wheels are.
jack up the unit on one side and block it, a 4x4 will work nicely.
then look on the side of the outrigger, you will see a slot, at the wheel axle there should be a roll pin inside the slot area at each axle.
use a long pin punch or something you can get in there to knock the pin out. Once the pin is out then you can get something else to knock the axle out, use something like a brass punch so it won't damage the axle.
The rest is easy to figure out.