I need tenant to move out.

[Liz F]

My tenant Lulu called me couple months ago to tell me she was moving out. Lulu has been there for one year so the lease term was no problem. I sent her a move out checklist. The end of the month came and Lulu showed no signs of being ready, she asked for another month. I said yes. During that time a prior tenant who is moving back into town wants to rent the house. Lulu told me that was moving on the 7th(tomorrow), but I just drove by and there is no way. Lulu always pays the rent (courtesy of the mother-in-law who is a delightful lady who I wish adopted all my tenants).
What can I do to make Lulu move? Can I refuse the rent? What to do?
My prospective tenant is as close to ideal so I do not want to loose him. He wants to move on the 25th, of course I have to clean, paint, would like to replace flooring, etc.

I appreciate any suggestions.