Even the garage car mechanic has got it very easy these days.
Big dealer garages.bmw/audi/Merc etc.
Back in the day a car mechanic knew the ins and outs of practically every car.
And had a wealth of knowledge.
Nowadays.if a car has a problem it's plugged into a pc the problem found and the part ordered.
Which comes in a pack with exactly the right amount of bolts.washers etc.not Even a spare bolt.
The job work sheet is printed out detailing the first thing to undo complete with pics.even giving the spanner size etc.
And the reverse procedure is the same.