Generally speaking, you can't change any of the information on an information return that you've received.
You should contact the issuer of your Form 1098 to ask for a corrected form. Also consider that, whatever information that they've reported to you, they've reported to the IRS, as well.
That said, you should check out the mortgage interest section in TurboTax Online, which could address your issue:
Select Tax Home in the left pane
On the Hi, let's keep working on your taxes! screen, select the dropdown to the right of Deductions & Credits
Select Pick up where you left off
On the Your tax breaks page, scroll down and select the dropdown to the right of Mortgage Interest
On the Your 1098 Summary page, select Start or Edit
Proceed through the screens until you reach the Let’s get the details from your 1098 screen