Boil it in a pot of water, then put it on with your wifes oven mits
the thermal expansion usually helps it slide on enough to then just install it with a bolt.
Don't Laugh!
Just make sure you do it NOW, and use the damned xmas mitts... (I HATE those dumb mitts)
"No honey, that's not grease on Rudolph's nose, it's uh... because he was brown nosing Santa!"
or,
"Santa and the reindeer were all greasy because they were out in Santa's mancave changing the transmission fluid on the sleigh for the big day!"
And you can tell her that if she doesn't believe in Santa, she gets a lump of coal!
They should be in a drawer for most of the year, so all the grease stains shouldn't be an issue for at least 340 or 318 (at most) days a year! If you end up in the doghouse, you should be able to get some cheap replacement mits for her on Boxing day.