I guess I would suggest to put a leash on him, have a handful of yummy treats and teach him to go in and out of the crate when you tell him to.

Thurston, kennel. Let him go in. Reward. Thurston, come. Gently pull/lure. Reward. Repeat. Not sure if this is right or wrong, it's just what I would do.

It's odd that a 7 year old would suddenly become THAT unwilling to come out of the crate. Has he had a complete medical check up lately? Have there been signs that he's in pain? That might cause him to not want to get up and come out as well.