i had this exact problem on my truck today..
79 Chevy 3/4 ton 4X4 with stock steel wheels.. the last time the wheels were off was about 2 years ago.
my solution- after trying to kick the passenger side wheel off by standing with my back to the truck and hitting it as squarely as i could with the bottom of my foot about 10 times- was to grab a 6X8X3 foot long wood block and throw it at the rim as hard as i could, aiming for the bead area for maximum leverage without having the tire throw the block back at me... the wheel fell right off.. move to driver's side- one throw of the magic block and it fell right off.
physics is fun.
if i had aluminum wheels, i'd use the power steering to do the work for me by placing a similar wood block between the wheel and the frame and turning the wheel against the block.. they pop right off when you do that.