Outgoing Tenant Not Cooperating with Letting Us Show Their Unit

[Jason L.]

I have a tenant who lives in one of my apartments who has given notice to move out on May 31st. I should note that I had a full-time property manager at the time she moved in (they have since been removed), and unfortunately they lost the only other key to the unit I would have had. So therefore this outgoing tenant currently has the only key to the unit.

I have reached out to the tenant twice to inform her that we are getting ready to re-lease her unit before she moves out. I was clear that her cooperation would be reflected when I evaluated her security deposit. She has not responded either time. The tenant has a history of being bad with communication, but I'm getting concerned given the circumstances. Because she has the only key, I'm concerned about what my options are to get access to the unit before May 31 when she (hopefully?) moves out. Remember I literally couldn't access this unit right now even if I tried. The only leverage I have is the security deposit, but once I threaten to not return it, she could easily just trash the place or even worse not leave at all.

One idea I've seen is to have a locksmith go change the locks while she's still living there (I'd give her notice I was doing this of course), give her a copy of the new key, and then charge her for the locksmith on her deposit. Again this could get tenant backlash on her way out, but at least I'd have my own key again and she could still presumably get back most of her deposit. Does this seem like a reasonable option? Can I legally have the locks changed while the lease is still in effect anyway?

Any other ideas out there?