How to change from itemized deduction to standard deduction in 2015

[macuser_22]

Why would you need to do that?

2015 is no longer supported.

Also you cannot claim any refund for any tax year prior to 2018 since the 3 year statute of limitations has run out.

[DoninGA]

Are you amending a 2015 tax return for a tax refund?  If so, it is to late to receive the refund for tax year 2015.  The tax return with a refund had to be filed or before April 15, 2019.