I need to change my mileage deductionswhere do I go Im getting down to the wire

Mileage for what?   You are not posting from Self-Employed.  If you are a W-2 employee you cannot deduct mileage on your federal return.  And what wire are you getting down to----it is only February 15----tax deadline is two months away.

W-2 employees cannot deduct job-related expenses on a federal return.  Job-related expenses were eliminated as a federal deduction for W-2 employees by the tax laws that changed for 2018 and beyond.  Your state tax laws might be different in AL, AR, CA, HI, MN, NY or PA.

https://ttlc.intuit.com/questions/4482873-which-federal-tax-deductions-have-been-suspended-by-tax-reform

If you were self-employed your business mileage goes on your Schedule C.  But you need to use the right software......you need online Self-Employed or any version of the CD/download.