Get your spanners out joe. I did the clutch in mine - not too difficult really, though manhandling the gearbox can be a pain. I'd also recommend buying a fairly decent clutch repair kit as i found the gearbox tricky to push back into place and had to tighten it with the bolts and i think that was due to the clutch kit.
In 9 out of 10 cases a low biting point is because of lost displacement due to air in the hydraulics. If it's a td4 try bleeding through to new fluid before doing anything more drastic.
I thort the DMF needs doing at the same time the clutch is done ??