Get the car up high, remove the driveshafts at the gearbox end (care required not to round the star bolts)
Drain the gearbox oil, remove the gearbox linkage & support the gearbox. Remove the front engine mount & gearbox mount (probably support the engine here as well)
Unbolt all the bolts holding the gearbox onto the engine & wrestle it free.
Then replace the clutch.