I saw a trick about the tabs for the backpack on MT Nova Prime. There is a screw on the backpack's left side that loosens the left and right halves. If you loosen it, it gives you more clearance to remove and replace the backpack. I spent about 10-20 min worrying about breaking the tabs before mine clicked on. At least now I won't have to worry about transforming it. I left a post in the Maketoys Hyper Novae, but decided to leave it here to make sure you got it.