You have to progress far enough in the game, and I think when bowser gets zapped in the toadstown caves, the pipeworks in bowser's body open up. You can enter these pipes, and they lead to different places in mushroom kingdom. After you get out, you have to find the rest of the pipes in the kingdom to be able to access them in the pipeworks.
You can get Beans, and an SP: Magic Window.
You can only do it with Mario and Luigi. For Mario, press A. For Luigi, press B.
You go through the pipes in bowsers body
noone
You have to complete the pumpworks level
No.
no
not really
Ok... first of all its FAWFUL not "farful" this is how you do it... You need to keep pressing x repeatedly until he go's in it actually works trust me. You fight him inside bowsers body as Mario and luigi (for a bit).
you have to hit the shell block.
first unlock the flame pipe area in bowser body then battle the boss that is covering the flame pipe
on the map