I am pretty psyched about cleaning it up tomorrow and grilling on Saturday, but one thing I am not sure how to do is remove the ash sweep assembly. I hope it's pretty easy! I also hope they don't break when I clean them and bend them a little so they fit snug against the bowl, because I don't have replacements on hand!
my experience with these is it just depends on how rusted it it. i've only un-installed the old style sweeps.
the first step i use is hitting the sweep mechanism with penetrating oil spray. i'm not a huge fan of WD40 but if that's all you have then give it a try. let it soak in for a while, i typically wait at least an hour hitting it "generously".
"IF" the bottom thumb screw breaks off while trying to twist it out, which has happened to me on more than 50% of them then... the key here is getting the sweep handle out of the nut so the nut passes up through the washer (in some cases) and kettle.
in this thread
http://weberkettleclub.com/forums/weber-kettles-accessories/don't-throw-away-that-old-weber!/ he drills out the nut from the bottom and states that the whole nut falls apart. i haven't gone this route.
i just hack sawed off both ends of the handle at the nut so the nut slid up through the kettle. then installed the newer style sweeps (weber part # 7444, $17.99 at my local ace) which were a direct replacement to what i had removed. i know people say you have to mod something, but i didn't. i just replaced the washer that came with the new sweep with the cross member bracket that holds the ash pan mount in place.
the important thing about hack sawing off the sweep handle that goes through the bolt is to try to do it right at the bolt. if you leave excess handle sticking out of the bolt you're risking taking the bolt through the washer and kettle bottom hole more difficult or impossible. you may end up having to cut it again which sucks.
good luck, let us know how it goes and be carefull around that beautiful green!