You start off with the small Path leading to a Launchpad. There will be a Open Area with 3 Octarians. Once splatted, take the Wall. With Checkpoint 1 out of the way, hide in the Ink and Splat him (only works in the back). Then take the next Launchpad to the 2nd Checkpoint. There are 3 Octarians on Crates. Once Splatted, the Launchpad appears. Checkpoint 3 reached, you'll throw a Bomb at the Octarians, shoot him. Once done, a new Launchpad appears. Checkpoint 4 is away, throw a Splat Bomb at the Octarians and kill them.