No guide, mate, but all you need is a phillips screwdriver & a pair of pliers, IIRC (it's been a while since I did mine, TBH).
1) Undo the 2 screws
2) Unplug the top sensor - release the cable from the side of the tank
3) Unclip the top hose - release the cable from the side of the tank
4) This is the tricky bit & you have to work fast, LOL. You have to take the bottom clip off, but be ready to pull the tank up & turn it on it's side QUICKLY to minimise the coolant spillage.
There maybe better ways out there, but I only lost a few drops.
