overall this is a simple process but be warned the radiator is very very easy to damage i have learnt the hard way so when i suggest caution it is because i already broke mine
under the car and remove the sump guard this is held on with lots of bolts and helps with the removal of the bottom half of the rad shroud.
unclip the pipe running along the top of the shroud, then un-bolt the rad shroud. as you are facing the truck on the left attached to the rad is a fan find the plug and undo, then unbolt the fan at the top push the shroud back and remove the fan (this is to cool the aircon rad)
remove the bottom section of the shroud this is a bit fiddly as it is clipped but it will come off, once off you sould be able to access the boldts that hold the fan to the clutch assembly. undo the and remove the fan blades.
CAUTION undo the bolts that attatch the cluch assembly to the pully. no be very careful and remove the clutch assembly without it hitting the rad as it comes off, i would advise you tape a bit of cardboard to protect the rad as i only tapped mine and it punctured the rad
once the clutch assembly has been removed you should now be able to persuade the fan shroud out. it is fiddly but it will come out.
now put back the small fan you removed and plug in. i opted for a 16" system from Kenlow with the small fan in place it only just fits and make sure the cable ties that hold the fan on are snug. follow the Kenlow instructions they are very straight forward.
once everything has been put in place and wired in nice and neat it is time to fire her up and run upto temp, once up to temp and the thermostat has opened let the temp needle just edge past the normal position then turn the dial (if using a Kenlowe) until you hear a click the fan should now cut in. and the temp should stableize and sit at normal.
that is it you are done. as we had problems with mine i do not have any pics to back this up. however it is a straight forward process if you are happy using spanners and know your way round under the bonnett of a car. failing that it is an hours work and should cost no more than fifty pound to get a man to to it.
it makes a big differance in my opinion no bogging from a standing start and the engine is keener to pull from low revs and feels smoother i will run a couple of tanks of fuel and let you know about economy over the next few days. also i can post a before and after pic.
hope this helps