I think the way to do it would be to unbolt the "head" on top, lay it in the grain tank, then pull the housing up and out from the top.
I ordered the entire clean grain elevator assembly, stainless, from the kit catalogue in August, and it just came in finally the end of November. I guess they are on build-as-order. It was $5600, that is crazy expensive, but considering what it all came with its not too bad. It is COMPLETE, I mean everything from bottom boot and door to the bubble up auger. Even came with the paddle chain, and even the #50 drive chain, tensioner, all sprockets, even the bubble up drive u-joint. And all completely assembled, just pull mine out and put this one it. Once I get it in the shop with a crane I don't think it will take much over an hour to change.
But I think they only have them for 88s, not 66s.
And I "think" lowen or worthington can get just the housing that you are looking for.
FYI there is 4600 sep. hrs on my elevator, I figured its shoveled over 4 mill bu of grain. Now I'd say its done well.