Any Five Year Old Can Do It is an episode of The Sooty Show.
Matthew is boasting to the others about how experienced he is in fixing things. Sooty and Sweep decide to construct a car using Sweep's new car making kit while Matthew decides to build a rocking chair with Scampi in the loft. While Sooty and Sweep are successful, things don't go well for Matthew when he finds he can't get it through the loft door.
Later he's still boasting that he is more experienced than Sooty, Sweep and Soo, so the others set him some challenges, first putting Sooty shapes back in the board and then a treasure hunt. Matthew fails them both and is extremely miserable. Soo repairs the rocking chair and makes a sponge cake only to find that she isn't perfect either when the cake is rock hard and the chair falls apart.
At night when everyone else is asleep, Sooty and Matthew work together to build a shelving unit that says on the box: "So easy to assemble that even a Five Year Old could do it."