Tax/Registration implications of changes to a Partnership LLC

My husband is the managing partner of a partnershp LLC.  They decided to end the partnership at the end of September and agreed terms of the split with an exchange of letters.A CPA friend has advised me that my husband will have to take steps to dissolve the partnership  for legal and tax purposes and file a return for a short tax year.  She has recommended he continues as a sole proprietor and files Schedule C for tax purposes.My husband wants to continue his business with minimum impact.  He thinks he can continue the partnership LLC, merely  replacing the old partner with a new one.  My research suggests that he can't just substitute one person for another (and there are presently no other partners in the business) and cannot avoid going through the process of dissolution altogether.To add further complication,the business will  have to relocate to a new state at the end of January.  Any advice?