Premium Acct can't add husband's exsisting acct that was previously premium now free

[PennyKnowlton72]

We used to be premium acct holders but due to financial burden we had to stop for awhile and just use the free acct.  Now I went back to the premium duo acct now instead of the family acct since my kids are starting to move on and I was able to recover all of my playlists but my husband is unable to link his app to the premium account link I have sent him.  If he deletes the app will he lose all his music lists? Please help me because this man does not have the patience and will not let me do it for him.