I've replaced my Gen 2's filter. It honestly wasn't that difficult; took maybe 20 minutes. You are correct in saying that you need a socket extender, but my dad had plenty of tools and once I got all the bolts off, it was a matter of pulling the glove compartment out, swapping filters (replacement cost me $17), and snapping the glove compartment back in. Could have been easier, but it wasn't intensive work in the slightest. The glove compartment is lightweight.
For some reason, I still have an odor in mine even after replacing the filter. It's only occasionally, and it only started happening after my car sat in my dealer's shop for 2.5 weeks waiting for a HV Battery Section 3 replacement to come in. It can only be described as a musty organic smell, almost like meat that's gone bad, but nowhere near as pungent.
So, your mileage may vary with a filter replacement. Mine is so infrequent, I'm not really planning on trying to get it fixed unless it gets worse.