The way I am interpreting this is there is a 2 member LLC being taxed as a partnership. One partner buys out the other partner and they dissolve that old 2 member LLC. There will be a final partnership return filed for old LLC. They actually both likely had their % ownership on the date it was finalized so you do not need to put 0% on each K-1. The final box will be checked on the 1065 and respective k-1s.
Then the remaining "partner" forms a single member LLC because it is no longer a partnership. That new LLC may elect to be taxed as a corporation then an S-corp if it files form 2553 and 8832. Otherwise a single member LLC will default to being taxed as a sole proprietorship, Sch C.