Do you have a freewheel tool? If yes, than prop the wheel against the wall so that when you turn with the wrench you drive it into the wall - that gives support. Find an extender for your wrench and give it a go. (Some penetrating oil helps like pb blaster/liquid wrench)

Otherwise for a price.. depends on the LBS/country/area. And it goes from free to a beer to maybe a few buck, idk.