Deductions & credits

I'm still confused on this question. So, for my first 1098 with my original loan, I enter in the outstanding mortgage principle amount in box 2, right? And then on the second 1098 for the refinanced loan I enter 0 in the outstanding mortgage principle  box 2, even though it has the new loan amount number in box 2? And then what do I enter in box 2 on the third Substitute 1098 from the lender who my refinanced loan was sold to?