some BRRR questions for the experts please

[JD Mims]

 I understand that you need to refinance after you have completed repairs. Specifically how does a refinance work? 

If I am all in at $100,000 and my after repair value is $180,000.. in the bank gives me 70% of that = $126,000.. Awesome, but exactly how does that Shake out? 

I now have a new loan for $180,000 do I have to put a down payment on to the new loan? like a new purchase?  or am I just financing straight $180,000?

and my mortgage payments are based on what 180,000+ whatever the interest rate is? or what?

I know silly questions but I appreciate any help. 

Thank you.