I've had the problem a couple of times.
First time it was enough to warm the engine and then leave the car overnight with the clutch pedal depressed. In the morning the clutch was free.
Second time (thought I would have learned) it was well and truly stuck. I tried overnight, then tried jacking up the rear and applying the brakes with the clutch depressed, then tried driving with the clutch depressed and in the end towed the car in gear with ignition off and clutch in, and it went after about 50 yards.
That's reminded me to check tomorrow as it hasn't been moved for a week or two....
Malcolm
