1996 Rover 4 Series 420d gear changing problems

Transmission problem
1996 Rover 4 Series Two Wheel Drive Manual 120000 miles

Hi,

Until yesterday morning my car was fine then, when I tried to set off to work, I could not put the car into gear. Tried a few times but nothing. Turned the car off and and hit the gear stick im temper, it went straight into first! Back to neutral and started the car again, would not go into gear! Switched off, straight into first, started the car and off it went, going up the gear box was not a problem but back down was difficult to impossible whilst the car was running.

To my limited knowledge this is a clutch problem and having search the internet likely to be either the master or slave cylinder but this is where the information seems to conflict. I have checked above the clutch pedal and this is dry and also checked the fluid level which seems to be full. The bit point on the clutch is non existant. Is it more likely to be the master or slave and how easy is it to change by a novice?