Upgrades are automatic and processed 3 days prior to departure. However, you must call NW to update your WP number in your reservation to be upgraded with GE. Looks like you missed the 3 day window but call anyway. Tell the agent to remove your WP# from your reservation (all reservations done prior to new status) and re-enter the #. Sounds silly but that is the only way for NW to recognize your new status on old reservations.