How do you change the clutch on a Nissan Sunny 1.4 LS?

This is a big job and not one for a novice mechanic.

yer i know it is ive done most of it but for some reason the clutch housing wont come off??? undone all the bolts around the casing got the drive shaft off....do i need to take both off???... done everything else i can think of anyone got any suggestions???