Unprotected sheet

Mehul Sheth (Audit Executive) (73 Points)

05 August 2019  
How do I unprotect the cells in itr 3?

whenever I am trying to select the option (yes/no) for the (whether you are a director in the company at any, time during the previous year.
it does not allow me to select the option yes or no. it says please unprotect the sheet. how do I do the same?