The current Pakenham station will see it's last train 8:48pm on the 17th of May, with the new one (and East Pakenham) opening in "early June"!

From the LXRP page:

From 9pm, Friday 17 May to early June, buses will replace trains between Berwick and Pakenham, as a crew of 200 work around the clock to demolish the existing Pakenham Station and finish the elevated 2.5 km rail bridge.

When trains return in early June, the level crossings will be gone, and the new Pakenham and East Pakenham stations will open to passengers.