Start the heart by using the screwdriver as an electric conductor with the live wire.
Get the tape recorder near the gremlin box so that he pops out. Hit him with the hammer.
Grab him and put him close to the button behind the glass, until he walks into it and presses it.
Then put him in the CPU.
Feed all the screws to the centipede, so that he's long enough to drag him into the GPU fan.