My mommom owned an accounting firm. She just passed away last week. As I am preparing for this tax season can you help me along the way? 

I tried applying for PTIN number. They want a business name and address. I would like to keep everything the same. How do I go about putting in from her name into my name? Her wish would be for me not to waste money/time with a lawyer even though that is an option. 

How do I get a CAF number? 

What other things should I get?

Thank you for your time. Please take it easy with the comments as I am sad enough.