Stay out of the water, and by extension the sand, of Colosseum by using the spikes as platforms. Morphing before landing on the spikes helps to be able to control the knockback. The final spike jump (which would be the most difficult) is avoided by doing a crouch jump into spring ball jump into IBJ to reach the left door. Perform the spring ball jump near max height. Place the first bomb between about 4 and 6 frames after the spring ball jump; ideally it should be just above the water line. Press pause between about 5 and 10 frames after placing the bomb, to disable Spring Ball (a 'spring fling', to reset fall speed). Place the second bomb soon after regaining control, while the game is fading back in.