Clutch Pedal Sticks On The Floor

Just got a freelander with a faulty clutch, There is plenty of bite in it just sometimes the pedal wont return off the floor and i'm unable to depress the clutch to change gear, So far ive tried bleeding it, The old fluid was black almost with some greyish slimey stuff at the bottom of the master cylinder resevoir, Put new DOT4 brake and clutch fluid in and bled the system the old fashioned way with the wife pressing the pedal up and down while i did the bleed nipple, If anything this made it a little worse so tried a new master cylinder and bled it from the bleed nipple by pushing fluid back up through towards the fluid resevoir using an oil can and some hose, this felt a bit better in the driveway but after a test drive clutch again stuck on the floor, So i guess its the slave cylinder that has failed and i've no option but to drop the gearbox off and replace it all but just thought id ask here first incase i'm doing something wrong,

I can't tell you if your clutch is faulty but here is a 'How To' if it is.
https://www.landyzone.co.uk/land-rover/clutch-change-in-a-td4-list-of-jobs-to-do.315242/