These things are best done when our big paws are little pups. they're easier to manage that way and always need to be reinforced.
don't get mad at me oK!?...i'm sure you did establish your dominance when yukon was a pup. it sounds like you didn't reinforce it on a forward basis.
start again.
when Grace has a treat or a toy and even thinks about growling at me when i get close to her or it i growl back...i climb on top of her and take it. i did, have and will always dominate her (i know that sounds rough, but it's not. I do dominate things.)
I square up, bulk out, growl, bark, nip, stare her down, whatever it takes. she knows just by my body language not to do that. she's so submissive to me that if i point at the ground, she knows to sit...or to lay down if she is sitting.
when i need to cut nails or look at a sore paw...i have no problem sitting on her and manuevering her feet or whatever. it's hard not to let up on our discipline...b
ut we have to keep at it every day.
it's a continual thing...you can't ever slack on it.
so square one for you and Yukon. get dominate. take control!!!!!!!