Basically, the partnership was dissolved on the date their were no longer two or more owners. So a final 1065 would need to be filed and depending on the state, if state registration of the partnership was required, then a partnership dissolution would need to be filed with that state.
The remaining owner will report all business income/expenses on SCH C of their personal return, with all business income/expenses being reported effective on the start date of the SMLLC.
TYpically, the start date of the SMLLC would be one day after the date the partnership was dissolved.
