Super Mario Bros. 3/World 8 Part 3

Part 1

 * Right at the beginning run forward. The Bowser statues here shoot lasers, and you don't want to get hit by these.
 * When you see a gap in the ceiling, walk to it and a platform will automatically transport you up. Once there, run to the right and onto the donut block to fall down again. After having climbed the stairs, you can get a hidden 1-up mushroom by jumping at the northeast corner.
 * The large area with donut blocks has four possible paths. The second one from the top just has a raccoon leaf, the bottommost one is a trap and leads back to the entrance. The topmost one and the third one from the top, however, lead to the second part.

Part 2

 * If you took the top path, the room looks like on the top map. If you took the bottom path, the room looks like on the bottom map. In both cases, go forward and jump over the Bowser statue. Only the first one shoots lasers, the others don't this time around.
 * The top path has large platforms of donut blocks and is thus easier. The bottom path has narrow blocks and is considered the harder path to take. In both cases, Bowser will start shooting flames at you which you have to avoid while crossing the lava pit.
 * The door at the end leads to part 3.

Part 3

 * Yes, there are two different Bowser fights! If you took the top path, it will be the top one, if you took the bottom path you'll arrive at the bottom one.
 * Bowser's attacking pattern consists of first shooting flames at you, then trying to buttstomp you which you have to avoid.
 * Unlike his Koopalings, you cannot jump on Bowser. However, the red brick blocks break when Bowser buttstomps them. Use this to your advantage by dodging him until he has dug all the way to the bottom. Once he has created a hole like this, he will fall down and die. The bottom Bowser is considered easier because it makes it much easier for Bowser to fall down.
 * You can also shoot fireballs at Bowser to defeat him, but it will be a long fight - he takes a total of 25 fireballs before he finally dies, which is sure to take a very long time.
 * If you managed to take Hammer Mario all the way to Bowser, you'll get a huge bonus - Bowser dies to three hammers thrown at him. Since he is largely stationary, it is dead easy to throw hammers at him (unlike Boom-Boom), which ensures a quick win.
 * After Bowser has died, wait until the fanfare ends. The door will open, enter it to rescue the Princess! The credits will start afterwards.
 * If you wish, you can start a new game after the credits have ended. There is no second quest for you, but instead you start out with 28 P-Wings - a large bonus!