Depreciation adjustments based on cost segregation study is not quite easy and staightforward if you do not made cost segregation study for your rental at its first year. 

It needs to reconcile the data between NEW accounting method and OLD accounting method. The differences are the adjustments need to entered at current year depreciation coloumns.

It will take time to figure out  the relatively compliciated calculations and math if it is your first Form 3115 without any guidence and training.