How do I change values in a picklist and ensure all old data is mass updated to the new picklist values?

How do I change values in a picklist and ensure all old data is mass updated to the new picklist values?

To replace all the existing Pick list option name to a different name in your records, we have the Replace value option in the Module & Field customization section.

To do this, follow the help link.

Please note, replacing the Pick list value will also change the modified date and time of the record.