Apparently Nexon has decided to skip the two-phase login-and-wait-a-week.
The package is available now (through the gift box notifier on the left of the screen) and can be claimed until March 14th.
To open it, you will need:
1 slot in Equip (will need two more later, to activate the Orchidroid coupon)
4 slots in Use
5 slots in Cash