At 72000 miles I thought I'd change my spark plugs on my '00 ML430.
So I bought 16 of them at $6.40 each from the local NAPA store B4418's 4 tip Platinum.

I did the passenger side first, removed the air box etc and coils. Took about an hour, taking my time.

Then I did the drivers side - I thought it'd be a little more difficult given the electrical fuse box etc getting in the way. Actually took me just under 40 minutes for this side, faster than the first, here's why.

Couple of tips.

1. The hardest part imho is getting the covers of the spark plugs - here's a tip which helped me.

When using a 17mm open ended spanner to pry off the spark plug covers, make sure you counter balance the leverage you're applying to ensure the cover comes off in line with the plug. Otherwise there's a tendency to push down on the cover which actually makes it very hard to remove. Also I gave the covers a slight tweak to rotate them a little first before attempting to lever them off.

2. When doing the drivers side make sure you cover the top of the exhuast heat shield - it has a very sharp edge and will cut your hands.

Hope this helps someone out and save a few $$$

PS there's more detailed info on how to change plugs elsewhere on this site and others - but nothing about how to remove the covers a little easier or how to avoid cutting your hands !

__________________
'00 ML430
'05 Mini Cooper S
'03 911 Twin Turbo
'03 VW Jetta