Separating a double lot into two lots

[Rodney Kuhl]

Previously we were offered the option to purchase a vacant lot that is connect to a lot that we own with a rental property on the land by the tax assessment office of Marion County in Indianapolis. The lot's taxes hadn't been paid so the assessor's office offered it to the owners of the two lots connected to it. But part of the deal was that we had to combine the new lot with the lot we already owned.

But now, lots in the area are going for a pretty high number, so we would like to separate the two lots and sell the vacant lot while still keeping the rental property on the other lot. Has anybody in Indianapolis done this before (I'd assume so), and if so, what steps do I need to take to separate the lots? And what are the costs to do so? Thanks in advance for any advice!