The archery on Castle Street

In the middle stretch of Castle Street stands the trolls' castle, with guards at its windows. How do you get in?
Nudge 1Where to look
Something is missing from the castle's mechanism: a wheel.
Nudge 2A stronger push
Once the wheel is in place, B at the spot below the castle starts the archery. And leave the prince's crossbow somewhere else first: carrying it, Dizzy only watches.
What you needOther problems to solve first
Solve these first (each opens its own page, no answers on the way):
Show the solutionThe whole answer, with a video
Fit the portcullis winch wheel (from the pirate ship's rigging, Up in the rigging) by dropping it in front of the castle. Then, without the crossbow in hand, stand below the castle and press B. In the archery, move the crosshair over a guard standing in his window and press jump to shoot; holding B raises the bow, which blocks what the guards throw back. Hit eight guards before the time runs out (you start with four hits; each guard's missile that lands takes one away). Then Dizzy walks into the castle.
Why it works
At the stall the game picks one of three rounds: the shooting (no crossbow carried), a round where Dizzy has no bow (crossbow carried: it always ends back on the street), and, once you've been inside, the walk in alone.