I'm sure most of you know,but a reminder,before you begin to unscrew each spark plug, make absolutely sure you have cleaned every single piece of crud from around the base of each plug,otherwise as you remove the plug the crud will fall into the cylinder. I always remove and fit the plugs one at a time.

Good advice!

I tend to blow any bits out with an airline blower nozzle. 

How many spark plugs do I need for my 2004 Alphard please. It's a 2.360 automatic.

Hi, 4 plugs. Plenty for sale on ebay,buy a good make i.e. Bosch.

I'd be careful buying items like spark plugs from eBay. Counterfeit parts are rife. Buy them from a reputable place. 

hello the factory plugs are denso k20ru-11 or you can upgrade to iridium plugs but more exspensive but worth it

Thanks everyone your message really helped