How do you free the girl with purple hair,she sais free me,rayman!fined..

There is a big pipe leading to her chamber. Follow it in the opposite direction through a tunnel. You'll have to fight one pirate, but after that keep going until you get to the barrel. Place yourself in front of it to pick the barrel up, then walk to the machine, as you get close to it, little floating bombs will come towards you. Press X to throw it in the air then shoot the bombs with Y. Rayman will automatically catch the barrel again. Don't move at all before the barrel is caught or you will miss it. Keep walking, repeating this process whenever a bomb gets close to you. When you get to the machine, stand near one of the giant crosses that look like two bandaids in a cross, then press Y. Rayman will throw the barrel at the cross and the machine will be damaged. Do this process another two times until all the crosses are gone. Then go back to Ly and she will be free.