Can anyone explain how to use existing equity in my current investment property to purchase another one?
You could get equity line of credit or take out a second mortgage on the property. The issue you would face though is that the payment on the first property will be higher and close to FMV but that would hopefully get offset by the second property. If you have enough equity in it, you could get equity line of credit and use it in place of HML so you don’t pay the upfront points till you sell or refinance the other property.
Yes. You can do a HELOC, home equity loan or cash refinance to finance the 2nd property.