I havent got any secrets mate!!!

A few tips mind:

Take your time!

Do just a bit of the arch at a time

Warm that area with a heat gun

- dont hold the gun too close

(dont want to blister the paint) and warm it up gradually, remember all you want to do is soften the paint so just warm to the touch is enough

It takes quite a bit of force to roll it so dont be a fraid to give it some stick

Regularly warm the area with the heat gun

Remove all the screws from the plastic trim parts around the wheel arch, as if you dont you could force the self tapping screws into the body work and they poke out through the wing

(I learnt this the hard way!!!)

90% of the time its just the top middle part of the arch that needs rolling anyway

Ensure the lip on the arch you are rolling is free from dirt, give it a quick clean out

The rear dampers may need unbolting at the top as the roller may be too long

You may need to take off the front calipers

(no need to take them completely off

- just unbolt them and get them out of the way) to get a full sweep of the arch

- although I didnt need to do this for my 8.5 inch wide fronts

- as like I say most of the time you only roll the top bit

To do an absolutely top job you remove the damper, remove the spring, pop the damper back on, roll the arch, pop the wheel on and compress the suspension with a jack to up to full bump to test if you wheel now goes past the arch without interference, this sounds long winded btu is often quicker in the long run rather than keep having to re-do it cos you havent rolled the arch enough.

HTH