How to Compare Merge Workbooks That Are Greyed Out

1. Share the workbook that needs to be compared and merged. This can be done by clicking 'Tools' then 'Share Workbook.' This is an initial step that needs to be completed before sending the workbook out to be reviewed.
2. Save all workbooks that have changes or additions with unique file names that differ from the original workbook's file name. Also, ensure they are all saved in the same folder as the original workbook before attempting to use the Compare and Merge feature.
3. Click the 'Compare and Merge Workbooks' buttons located on the toolbar. When prompted, select the workbooks that you wish to merge into the original, and click 'OK.' You can merge multiple copies of the workbook by pressing 'Shift' while you are selecting the various workbooks.