This level is fairly hard for inexperienced players, but easy once you get the hang of it. As soon as you enter the level slap hands so that Diddy is leading. Bounce on the tire and land on top of the building. Once there jump straight up. You hit a barrel blast. You only have one chance* at getting what you want.
Make your choice and you will be shot back into the level. Proceed from there.
Donkey will have to take the lead now. There are two Krushas up there. Diddy can't kill them, unless he uses the TNT barrels. Pick one up and throw it at the first Krusha. Do the same with the next one.