sounds like you have bent your bb .. new bb should fix it but to get your cranks off , you need a crank tool , the larger bit of the tool goes in 1st , just screw it into your cranks , then the smaller bolt screws in after that , dont forget the put the small metal bit at the end though , then rench the bolt up tight , and they should just fall off .. if you need them off quick , and there square taper , which the t comp ones are , then just put a cloth round the crank arm and a heafty few wacks with a hammer should sort it all out