Adding Member to LLC. 8832 and EIN?

[Tanh Truong]

Hello Everyone

My partner has filed for an LLC (Cincinnati, Ohio) back in February as a single member and we have made an Amendment to include me as a 50% owner in the LLC. Currently, I believe the LLC is classified as a sole proprietorship/disregarded entity. I have a three-part question.

1. Would I have to file form 8832 to change our classification to a partnership or will it change by default? 

2. I've read that this requires a new EIN. What are the steps for this process? Does it have to follow in line with filing the form 8832, if a filing is needed?

3. We are also filed with the city of Cincinnati (local witholding tax) and the current location has a 2.1% witholding tax rate. We plan on changing the location of the business address to avoid this tax. Does anyone know the process behind this? 

Any and all information will be greatly appreciated! Thanks in advance.