They are easy-ish providing you have all the parts ready

http://www.ebay.co.uk/itm/AP-Style-R...3D150773662324

http://www.ebay.co.uk/itm/BRAKE-CLUT...item417844ccc3

or Girling which kits come with

http://www.ebay.co.uk/itm/Girling-Ma...item25640ee699

Slave cylinder

http://www.ebay.co.uk/itm/CLUTCH-SLA...item2ecf1ed877

Small female fitting for the clutch release arm for the slave rod to push in to

and the bell needs modding but you need to get it as close to the transmission housing as possible