I had to change the clutch cylinder under the pedal like you are going to have to because before long it will 1. Get very messy 2. be very slippery 3. eventually go..
However, when i did mine you take the two fluid lines that go into the bulkhead off and inbetween both of them should be a bolt, undo this and then there is also a self tapping screw holding the cylinder onto the pedal undo that and it should come out easily enough. (lots of rag to take up the fluid)
Now refit the new cylinder, the trouble i had with it was its a complete pain in the ass to get a new self tapping bolt back in under the pedal! i found ratchit spanners very useful at this point! once all is refitted bleed it up (clutch nipple is ontop of the gearbox, but dont do this up to tight because if you snap it, you have to get the gearbox out!!) it took ages to get the fluid through on mine so keep at it and it will eventually bleed up
Sounds like your focus is riddled with trouble best of luck to you