Unhide the sheet first : just in case it is hidden right-click on the name of any sheet and select Unhide from the popup menu.This will show up the unhide sheet dialog box.Now choose the sheet and click ok and follow the steps given below.
First of all press Alt+F11 to display the VBA Editor. At the side bar there will be a part that says Modules or forms.Now right click the module or form and hit Remove
If you don’t want to individually remove the macros it is better to follow this approach.
Here is an code that can help you to remove all the macros and modules from a excel file. You have to click on the image to get full tutorial on how to do it.
One of the way to remove all VBA code from a sheet that consists macro is to save that file in a macro-free format that is you can save your .xlsb workbook as .xlsx
For those who are using Kutools
Apply this utility by clicking Kutools > Delete > Remove All Macros