"Tenants In My Newly Acquired Building Are Stealing Building Materials"

I just bought a landed property on the mainland in Lagos. The current tenant begged to stay pending when they get an accommodation elsewhere and they were given 2 months plus to move out. The previous owner served them quit notice and did not collect rent from them in the last one year. However, the agent that helped in buying the property called me that they have started removing windows, wires and doors from the flats that are already vacant.
Currently, I am at a cross road as to what to do because my intention is to renovate the property once they all move out.