Lock change - when can I do it?

[Larry Bowers]

I made a secured loan on a house in Missouri, but borrower stopped paying. The house is newly refurbished, in a desirable area, is vacant, and is being marketed now for a tenant. New “white goods” like a range, microwave, fridge, etc. are in the house. I will probably get the house after the auction. 
Shall I have someone poised to change the locks? Same day as auction or if later, then when?
Do those white goods become mine?