Cashout refinance BRRR (please explain)

[Lee Griswold]

My first House I bought when I was 25 for 90,000. It is a 2 bed 1 bath single family. I have 7 yrs left on my loan and I owe 36,000.  The mortgage payment is 800 a month. At my last appraisal it was worth 140,000. I currently get a 1000 a month in rent. if I do a cash out refinance how much capital can i take out? Will the property cash flow (or is it cash flowing now). So can someone help me run the numbers and explain to me the how and why, so  I can run them my self in the future?