The bloke in that video makes it seem easier than it is in practise! Just breaking the bead and re-seating it after can be difficult. It may be an idea to give it a go though when you get the new tyres, just practise on an old one a couple of times so you have the ability if caught out offroad with a puncture on a long rainy trip! But then if you don't carry all the axle tools and tubes and repair kit including three levers, valve core tool, high pressure pump, windex, baby powder etc etc, it may be best to join RAC or AA! Southampton is not exactly the outback eh?