Do I need any special tools for the fan removal as Rave shows that I do? And Do I have to take the fan or rad out to get to the thermostat?
You definitely need to remove the fan, to access the thermostat and it's related pipes.
These are only one-piece items, I bought a 2-piece one which holds the pulley still whist the other actually undoes the fan.
TD5 fan spanner | eBay
You do not need to remove the rad, although it might make sense to flush it through with a hosepipe whilst the pipes are disconnected.
Bits you will need to buy:
1. OAT pink coolant - get 10ltrs just in case. You will probably use about 5ltrs;
2. A selection of good quality Jubilee clips to replace the original spring type ones.
3. The thermostat itself.
NB It is vitally important that you refill & bleed the cooling system fully before the job is finished. Failure to do can result in air-locks which are not good for the engine. See Rave for the procedure.
Have you checked yet to see if your viscous fan is locked? If it has this can also cause too much cooling and increased fuel consumption.
After the engine has warmed through, turn it off and check the fan - it should turn relatively easily. If it doesn't it's locked on, so not working correctly. Needs replacing.
Good luck
Dave