For the second part you have to aim so you hit the float bubble, float up and hit that bomb and then land in the centre of that break line, hitting the rebirth bubble along the way. When the line breaks you'll fall back down, hit the rebirth bubble again, fall down, a bomb will deal with the power down bubble and you'll hit the speed bubble. The rest is easy!
Start with jumping over the first two bubbles that are on the ground to get the third (stop sign) and at the same time to be bumped back by the fourth one...this way you get all of the 13 bubbles in one go, next 32 left for you to find out...