For anything up thru 9 speed cartridge type,you need a shimano cartridge BB tool. For pre cartridge type you need different tools. 10 speed type uses an even different tool. Any might be removed with a big pipe wrench if you are a real Bubba.
Before you take anything apart, suggest just dropping the chain off the inside chainring and spinning the crank with your fingers. If the bearings are bad, they'll feel rough and noisy.
If you need a new BB, you could visit to a good LBS who have the right tools and knowledge. They shouldn't charge that much for the service, and you'll know everything has been properly assembled and tightened.