Tenant wants to terminate lease early

[Kevin Huang]

Just received a text from one of my tenants yesterday stating that they intended to terminate their lease early at the end of the month.  These tenants have been a royal pain in my rear end lately, and honestly I would be more than happy to have them leave.

The lease they signed (expiring on 8/31/21) didn't include a buyout clause and doesn't appear to have any language surrounding early terminations, so I wanted to pick your brains on what my best course of action is going forward.  As much as I want them out of the property so that I can get better tenants in by Summer, I would still like to charge them some amount to cover for the missed income until then.  As this is my first time going through something like this, I'm not totally sure what my rights are and what would be a reasonable amount to ask for.

Some additional background:

I live in Chicago in an owner occupied 3-flat, and the tenants live in one of the bottom units.  Form the research I've done, I believe that this exempts me from the Chicago RLTO, although I don't really know a whole lot beyond that.
The unit they are living in has recently experienced some issues - a faulty appliance that I replaced in a timely manner, and some water leakage caused by ice damming due to the record snowstorm this past winter (which I am still in-process of fixing).  They stated in their text notifying me of their intentions to terminate early that they took issue with me not providing 2 days advance notice of needing to enter their unit, however I don't believe this is a valid excuse (I've never once entered into their unit without asking their permission first, and every time it has been to address repairs that they have requested).

Thank you in advance for your help!