1) Watch the episode of Transformers called Microbots.

2) At the beginning, Prime, Ratchet and Bumblebee go on a mission.

3) Prime then gets shot by Megatron, and suddenly Bumblebee is replaced by Cliffjumper!

4) Suddenly, Ironhide, Bluestreak, Brawn, Hoist, Grapple, Wheeljack, Huffer, Smokescreen, and about half the Autobots are on the mission!