Got the judgment and tenant was ordered to vacate the premises last Thursday.The tenant is still there and the elderly lady's son wants her to change the locks and not file a Writ of Possession.

I took the house on vacant possession as it is full tented with the basement apartment and the three bedrooms upstairs.

How do i take complete possession of property..Do i have the right to change locks to property

From what I've been told, they are great people and great tenants, but if I take possession of the house, I'd like to increase the rents to be somewhat closer to market rate.

This is your property and ultimately YOU decide who will be taking possession.

Several properties in a land trust, just the cost to clear them in the land court can cost a small fortune and before anything is sold You could always market them yourself if they are in your possession.

You need to get possession at the close of the deal. 

., they just have to possess cross boarder real estate and/or business experiences (wholesaling would actually be regular income, not investment/passive income, and would create different criteria for a Canadian earning foreign income).   

I have a renter who paid a deposit, took possession of the keys and signed a 1year lease but now is talking about backing out and not moving in.

Even if you don't have keys you can still take possession back.