You need a card like a credit card to open the Laundry Room at Greg's house. Once you have retrieved the Twisted Wizard guide from the school (and chased Manny as far as Leisure Towers), you can beat the game yourself. When you return the CD to Rowley, he gives you his Joshie Club card that will work on the door (you want to turn off the power to Rodrick's room).
Use it to open the laundry room door at Gregs house.
You shut the front door
You can't open the door. It has no use for completing Wimpy Wonderland
Right next door to Greg's house (to the left). The second house over is Rowley's house (the Jeffersons).
you open the laundry room door with it in Greg's house.
you don't.
It is inside Greg's house. Use the membership card to unjam the door.
Open up the locked door in Greg's house.
You jump on the truck first and then quickly touch the bush next to their house door to hide from him which then allows you access to their house
Use it to open the door that is to the left of the front door once you enter Greg's house. For information or walkthroughs go to poptropicasecrets.com.
After you jump on the car you quickly hide in the bush to the left of the front door and sneak in the house when he leaves.
Jump on his dad's car, and when the alarm goes off hide in the bushes and then click the door.