One major one--do them from the bottom. I can't imagine trying it from the top, just don't see how that could possibly be easier.
Otherwise, here's what I learned when I was changing mine: http://www.subaruoutback.org/forums...40473-h6-plug-change-not-quite-bad-hyped.html
Otherwise, here's what I learned when I was changing mine: http://www.subaruoutback.org/forums...40473-h6-plug-change-not-quite-bad-hyped.html