|Source: the local data company|
- Place bike on bike stand, or turn upside down.
- Let out air from tyre.
- Insert screw and nut and tighten using longish allen key or equivalent as there's now room to get at it.
- Re-inflate tyre. Ride off, feeling happy.
They also play 6Music in the shop, for which they should immediately get a gold medal for services to cyclists.
Curious fact: I can't actually find a website for Cavendish cycles. Perhaps they don't have one?