Changing locks (Commercial Property)

[David Peskind]

Hello all, 

I have a commercial tenant who's lease is coming to an end at the end of November. Currently, I received an LOI from a new company wanting to take over the property. I am concerned with the current tenant not wanting to move out of the property, even though I have already given 30 day notice. I am wondering if it is legal to change the locks of the building once the lease (and notice) are up, before going through the eviction process. The property is located in Illinois.

Thanks for you input.