So the mortgagees must follow specific procedural rules when trying to divest an IRS Tax Lien (or any federal liens for that matter).

I'd consult an attorney before changing the locks and if making a key to enter, follow proper procedure to advance notify them of your intent to enter.

The legal/procedural overhead of a private placement is too high for a small deal like that.

Talk to a local title company if you don’t know the implications of a tax deed......the laws, procedures and restrictions are state specific.  

A "professional" tenant can tie you up in court for the best part of a year, especially if you make even a tiny procedural mistake.Chapter 93A (the Consumer Protection Act) also applies to landlords and can award a plaintiff up to 3 X damages.

I’d also brush up on eviction procedures to prepare in case payment isn’t made.

Thank you for the procedural advice.

I took a full video of the apartment upon move-in with myself and the tenant in the video and have numerous photos & videos of the condition of the apartment when vacated.I want to bill the tenants for the damages but want to make sure I follow the laws/procedures correctly. 

What is the procedure for changing the locks in Chicago and providing the keys to the tenants. 

Specific notices and procedures are required to file a legit lien in FL.