Investors & landlords

I need to split my Mortgage Interest, Real Estate Taxes and Home Owners Insurance for renting my home for part of the year again this year. I was able to enter an amount directly in line 10 Home mortgage interest in Schedule A and things recalculated. But I'm unable to reduce/edit the total of the Mortgage interest qualified in line 12a on the Schedule E Wks. Clicking in the field makes the + to the left of the field appear and in the pop up window I can enter a description and an amount but the amount doesn't update the value on the Schedule E Wks. Where in TT Step by Step or in the Forms can I make this edit? We received a few 1098 forms for paying off mortgages with a refinance. Should I change the amounts on each of those in the Report Mortgage Interest page to the Rental Use Percentage of the actual amount?