If I remember correctly..you have walk over a SPOT in the center of the room and a series of colums come up.
Then you have to JUMP A LOT.
Go to your left and smash the brambles. Then walk over to the shed. Go in, and look up. You will see an oil can. use that to open the rusty gates.
Go back and make sure you didn't miss any snakes.
I found some cheats, so I now can help you. You can find the boots (or shoelaces, i'm not sure) in the shed above the door in Uncle Monty's garden. To get the boots, use the bopper or the flinger to knock over the watering cans that hang near the second floor window.Then giant flowers grow. Jump on them to get the boots.