If your employee e.g. changes their contract from full-time to part-time, here are the recommended steps:
1. Check current employee profile and:
Export future & accepted or waiting for approval requests (Reports → Requests)
Export the limit information you need to transfer to the new profile (Reports → Entitlement)
Check also: How can I export reports?
3. Add a new profile and:
Set the appropriate leave limit, taking into account the limit from the previous profile and the limit associated with the new work schedule/contract