You don't need to unscrew the bolts all the way out of the coilpacks to remove them.
Just unthread them to the point that it's out of the head and then pull the coilpack out with the bolt still in it.
A 10mm combination wrench is your best bet for this.
Moving the windshield washer bottle helps, too (not to mention the airbox).
Complaining about changing sparkplugs on a Subaru??? These cars are a piece of cake - you guys obviously have no experience with small block Chevy's or transverse V6's where you have to take the intake manifold off to get the rear bank
It's a 10 -15 minute job max