To edit an employee's contract end date on the system, this can be done by following the below steps:
Search for the employee using the organisation search then click the Employment tab.
Within the employment tab, click into Position.
Once you are within position screen, click Edit next to Employment (Primary)
Remove the contract end date from the Contract End Date field.
Click Save.
📌Note: You need to run batch update on the system for this to appear correct.