Schnellfahrer,
Just my two cents, but, I've done numerous sparkplug changes on my 99 Boxster (288,200 miles). I've always had good success using a combination of these two tools to remove the two bolts holding each coil (The Allen wrench hex key tool I purchased at Harbor Freight and the small ratchet/screw driver bit set I got at Walmart). My biggest issue is letting the engine cool down so I don't burn my hands and fingers.
The first time I changed plugs it took me quite awhile to remove the front most coils and plugs on both sides. It just takes some patience. I've always used a lift to change my plugs (being able to stand under the side of the car gives you better access), but it can be done just as easily using jack stands. Last week I changed a center sparkplug tube on my Boxster using jack stands. I had changed out two sparkplug tubes before using a lift. It was a bit more difficult using the jack stands, but it can be done. You might try putting some large square wooden planks under the jack stands to get the car up a bit higher.
Best of luck.
MNC-I
