There are two ways of updating Existing Work History in Mercury:
1. Re-send the Candidate's updated CV to your Mercury CV email address, that would re-parse the CV and would attach a new document version to the Candidate's record.
2. Update the Work History fields manually or add a New Work History.
Contacts > Contact record > Experience tab > Check the tick-box of selected work history > Click Edit
Update the fields necessary, including General information, Dates, and Address Details.
You can also + New Work History if you need to add a new job.
Complete at least the mandatory required fields, which are marked by a red asterisk (*), then click Save and Close.