In downtown, walk to the left of Patrick. Enter the jewelry store. Talk to the person behind the counter to get the videotape.
Enter the WCEA station. Enter the room under the stairs to the news room. Enter the broadcast room and talk to Plankton. Do what he asks, then talk to him again to get the videotape.
Enter Sponge Bob's house. Open the closet door on the wall to the right.
In Oxygen Springs, enter the building with Patrick's pants. Open the Davey Jones' Locker door to the right to find the videotape.