As I said, you will need an assistant first to see what the cable is actually doing at the clutch end while you press the clutch pedal down. It *is* possible for one person to do this check but it's MUCH easier and faster with two.
If it's just a case of readjusting the cable, then it's easily done in the engine bay. Again, 2 people makes the job fairly straightforward. If the cable is broken or mis-routed somewhere, then it's not a difficult job to replace, but it IS fiddly and time-consuming. Most of the time is taken in removing trim and covers, and actually finding a way that works for you to get your head and hands up under the steering wheel to reach the front cable end, and to route the replacement cable into place.
In my experience you should allow a whole day to change this cable if you are not experienced in this sort of thing. It is NOT a ten minutes job! It's one of those jobs that, if everything goes well and there's no corrosion or blockage and the wire doesn't kink and everything lines up properly first time, could take as little as an hour, 2 at most. But if anything goes wrong it tends to grow horns and one fault leads to another...
For a garage to do it, I would expect no more than 1 hour of labour charge.
