If your vacation plan has been approved, but you need to make changes to it, you will need to contact your HR department. You can do this directly in LabOrders.
1) Go to menu Projects > Vacation Approvals.
2) In the line of the vacation plan you need to make changes to, click the Actions menu arrow, and choose Email Users.
3) In the following screen, you can choose the person you want to contact and explain the changes you need to make. That person will then be able to unlock your plan, so the changes can be made.