year 2005.
i've cruised the forums, and apparently it is very difficult. clearances are super tight to the frame of the body. i have the turbo, so there are individual coil packs to deal with. i have about 1.25" of clearance for the rear sparkplug on the driver side. it looks undoable!!
the internets says alot of people disconnect the motor mounts and lift the engine to clear the frame/car body. i talked to a subaru shop (quoted me $825 to do the 60,000 mile service) and he said he has never heard of having to lift the motor. the coil pack + spark-plug boot has to be about 5" alone..no?
here is a pic.. that black cord you see in the middle is the wire for the front coil pack drivers side..no wiggling of camera phone could capture the rear.