SMLLC. right now treated as a Schedule C.

Owner wants to bring in a partner with ownership rights.  I was under the impression that form 2553 would not help in this case since the current legal entity is owned by one person.  I may be wrong on this but wouldn't a new company have to be set up.. say a MMLC and file form 2553 or can we use the existing structure.  In either case we would not need 8832, right? Thank you.