They are probably looking at the fork that forms the base of the spring/damper unit. Tends to be a nuisance (can't swing the driveshaft to one side) and may be difficult to remove.
It all comes down really to whether the driveshaft can be separated easily from the outer joint (may be a square-section circlip on the shaft under the boot, or may be a jump ring (circular-section) on the end of the shaft that you can't see and have to knock off). I've even heard rumours that 156 driveshafts are 'one piece' and that the shaft can't be separated from the centre of the outer joint. That would make things a lot worse, as you'd have to take the inner joint off the shaft (six Allen bolts, circlip) before you slide the boot off the outer joint. Perhaps your mechanics are operating under that plan?
On my 156, both inner joint boots failed while the outer joint boots were fine, so I suggest a critical inspection of the inner boots while the driveshaft is disconnected.
You could alternatively unbolt the 'axle nut' and get the outer joint out of the hub carrier, then use a boot stretcher tool (sometimes a large cone, sometimes air-powered fingers) to get a new stretchy boot right over the outer joint body.
So there are several ways to do the job and if you think it looks simple, perhaps you should do it yourself, I would
Another thing to remember is that it takes time to wipe away all the old green grease, and then you have the chance to play with the big-shiny-balls Chinese puzzle, where it only fits together one way to swivel properly. Then you add only the finest dark-grey pasty grease with the Molybdenum Disulphide, pushing it around the balls with your fingers and making a huge slippery mess for the boot to clamp onto - not forgetting to use the metal band clamps (and special tool) rather than cable ties (which have insufficient tension).
Will the average garage staff bother to clean/play with your balls and use metal bands? Yeah, I'd rather do the job myself