When bowser throws his spiked bombs at you wait for them to stop moving. Then pick them up with you vacuum. Then you have to wait till bowser lowers his head to breath fire or to breath you into his mouth and shoot it at his mouth the head will pop off and boo will pop out now turn on the vacuum and lower his health points while avoiding the ice blasts that comm from bowsers head. Repeat this process and you will beat bowser.