How to recover the data of a protected Excel Sheet
We are speaking here about a protected sheet. Meaning you can open it but cannot change its content. If you are looking to open a protected Excel File, then this is another issue and only brute force decryption can be used here. There are plenty of programs on the net that do this. Just google for Excel Recovery Password Software and try one of the programs proposed.
Advise: use only Sw from know sites like CNET, TUCOW or GNU or Sourceforge eventually.
But anyway here we are speaking about Sheet protection.
1) think deeply about what password you could have chosen...., sleep over it. Next time write it down.
2) Or second solution is to copy and paste every page of the workbook into another new workbook.