You can get the Sweater by going into the leftmost room on the first floor of the Present Day mansion. Use the Dime from the pay phone and the Dime that was embedded in the gum in the coin slot at the back of the room, and the man will be sent crashing to the floor.
Once you've done that, go down into the laundry room, which is the door on the right in the kitchen. Put the sweater in the dryer, and use the Quarters that you should have got out of the candy machine on the first floor. If you haven't, a good clue is to use the crowbar.
As Laverne, go into the Laundry Room. The machine should finish, and the sweater will now be dry... but also ridiculously small. But also toasty warm. Now, don't you have something that is rather cold and wet?