novice user with the most novice question.

I have a workbook "August 2016.xlsm" which has several macros (created by others). One macro is "PERSONAL.XLSB!test1" which I want to delete.
I know that to delete, I must Unhide the Personal Workbook. But right click on a worksheet and Unhide is greyed out.
I have been googling for some time but all answers are for some other issue, not this one.

thanks.