Just run past the window when the guard's shadow isn't visible on the shades.
There are no snowballs on Counterfeit Island. (see the related question)
Wait until her shadow moves away from the Security Room window, then run across.
Go through the hatch and try to get past the museum security till you get to the scream painting.
To pass the Security Room, wait until the guard's shadow is no longer on the window.
You have to get a balloon.
In the upper left of the museum.
you have to take the underground tour
the security guard is at Bobo's clown store
He is in the BoBo Clown Store
He is in Bobo clown shop.
in the lighted room on the second floor