Expense deduction / Depreciation schedule for multifamily building

I have a 3 family building whose occupancy was as follows for 2018.  How should I prorate the expense deductions and depreciation schedule?

 

Unit #1 Available for rent January 1.  Rented on April 20th.

 

Unit #2 Available for rent January 1.  Gave up trying to rent it May 2018.  I took over residence of the unit on December 1, 2018.

 

Unit #3 Available for rentJanuary 1. Gave up trying to rent it May 2018.  Started gut renovation on unit sometime in October 2018.

 

The units are all somewhat old and need a lot of TLC.  That's why they were difficult to rent to credit-worthy tenants.