If you need to update a large number of records in Salesforce, you can use Salesforce reports to simplify the process. A common use case is updating the value of a field across all records created by a Play. However, these steps are generally applicable to any set of Salesforce records.
In the top-right corner of the screen, if you click the menu icon and search for “reports”, you should see a link to get there.
In the top-right corner of the screen, select New Report
Choose a report type based on which type of records you need to update, and then click Start Report on the right
Be sure to add the Id column to your report in the sidebar, which is typically named after the record type you are selecting (e.g., Account ID, Contact ID, etc.)
Also add any additional columns that you wish to edit on the records
Add any filters or sorting options needed to narrow down the records you want to update
When ready, click Save in the top-right corner, enter a name, and then click Save again
Click Run in the top-right corner and verify these are the records you want to update
Click the dropdown arrow next to Edit in the top-right corner and select Export
Choose Details Only and Comma Delimited .csv as the format and then click Export