If the two acres are not yet seperately defined, you will first need to find out if the property can be split. The township assesor will likely be the place to start. If it is splitable, you will need to have a surveyor survey the property and provide the seperate legal descriptions. This will allow you to have the assesor assign two seperate tax id numbers. Then refer back to the first paragraph for the additional steps.
I hope this information helps! Best Wishes!