How do I replace the blades in an AirHogs Switchblade plane?

"For the Air Hogs Switchblade model, that we bought in 2016, it worked a bit different for the bottom blade:

The bottom blade was secured by a 4 mm tall, round, grey plastic socket.I warmed the socket with a hair dryer and then pulled it off with a pair of tongs.Then the bottom blade was easy to pull off with my hand."