I know how to change the pads on my Zed as I have been shown but I would pay £40 for someone to do it for me. Don't get me wrong I love a bargain but I am no expert and if I did something wrong it would cause a LOT more than £40 worth of damage
Same reason I paid someone to change my plugs, I could have caused a whole heap of trouble if I did something wrong
I have though spend thousands of pounds on electrical equipment and taken it apart straight away to find out if I could 'improve' it, everyone is different
Just because you pay someone to change parts on your pride and joy shouldn't be a reason to have a pop, remember what happened when Husky installed his plenum spacer, or Bennett 'helped' change Ian's plugs