Ive never looked at a 66 with choppers, ours has spreaders. There should be 4 bolts on each walker block, front and back, take the bolts out and it should pop out.
YC... The straw walkers come out the back of the combine. Take out the swinging door above the chopper then take out the back panel tin.Unbolt the walker from the wooden blocks and slide it out the rear end.Not to bad of a job...Good luck