Firstly you will need a 16 mm plug socket. Go on to ebay and buy a 3/8" drive magnetic version with a UJ joint piece as part of the socket, dirt cheap! Adequate extension bars will be required as they sit deep in the head. You will appreciate the magnetic function when you use it. When you crack the plug loose before removal make sure you get all the water out, I use a syringe and tube then an air line to dry. Don't be in a hurry to get the plug out. If its clearly corroded and the body rusted start to remove it a few turns and then re fit gently repeating this process. squirt some plus gas or similar down the hole and continue the removal process until about 3/4 way out. Now blow or suck out any debris that will now be sitting around the base of the plug and check its clear then finally remove the plug. You can see clearly the state of things now with a torch. Fit new plug as described earlier and use a dielectric grease on the coil/plug boot and top of plug.
If you look in your hand book it will list the plug type, I would recommend NGK as a brand, there are spark plug comparison sites which will give you the options for different makes. Physically compare size of new with old prior to fitting as subtle length difference can matter!
Thank you sewin this is extremely helpful. Magnetic spark plug socket with UJ fitting, dialectric grease, ceramic lubricant, a can of compressed air, and some NGK plugs are on order. Water extraction mechanism subject to further research once I've had a chance to pull the coils and have sight of the depth of the plug wells. Again, excellent and clear advice, much appreciated!!
