I'll vouch for all the responses above...
It's one of those jobs that, if the clips are rusted and/or the (original alloy) airbag ends have corroded and stuck themselves to the axle or chassis, it will take a while to pry them free.
It can be a right pig to get the airbags out, but no skill is required and the rest is very basic work...no special knowledge or experience required.
A garage will charge you an arm and a leg for basically levering the airbag end caps with a pry bar and whacking them with a hammer...something I'd rather not be paying for!!!
Do iy yourself and you can also spend a little time Hammeriting all the scratches in the chassis or axle you've made. Doubt any garage would do that for you.
Malcolm