He’s a real pest, destroying every screen opening in my roof, clawing out the insulation and dumping it all over the lawn, coming down the stove vent pipe in the middle of the night, making a racket, and having loud chattering hissing arguments with the neighbor’s cat.
But my wife says not to kill it.
You need a humane trap or a “live trap” (example here)
Drive it far, far away. Let it ruin someone else’s house 
This is a let down. I thought the title read “I want to get rid of a squirrelly human” and I had some suggestions. None of them are humane, so I’ll just save them for later.
Can you get a cat yourself? Even borrow one for a while? My own cats, who are terrible hunters, are none the less effective at staring down rats and squirrels.
Otherwise, trap and release at your local college campus. Most animal shelters and veterinary clinics will loan you humane traps for nominal fees.
Grease the inside of stovepipe, starting several feet from the top.
Set up several hobby rockets inside the stovepipe at the bottom.
Set them to trigger when something impacts the bowl on top of them.
Call NASA to warn them of the impending first squirrel in orbit.
**ZipperJJ **That trap looks good, and is cheaper than I guessed, but it says it’s for red squirrels. Mine’s gray.
**Bobotheoptimist **I wonder if your ideas might work on a squirrelly non-human. Let’s hear them.
lieu I didn’t get that video to display, but with a name like “squirrel launcher!” I can guess the missus would not be amused.
pullet As noted, the squirrel is not intimidated by cats.
**hotflungwok **Now you’re talking with gas! Sub-orbital animals are humane, right? Doesn’t NASA use them?
My father traps our troublesome squirrels in a live trap. A bit of bait (peanuts, I think). Then he drives them far, far away (preferably to the other side of a river), and releases them. They get a happy squirrelly life in a nice big park, and we get less of a problem with they chewing our house and, on occasion, breaking into our kitchen to steal vegetables (for real).
Killing a squirrel should be done as inhumanely as possible. Fuckers.
Trunk - My first inclination was to be inhumane, but now I’ve been persuaded by the Supreme Court that 3-step lethal injection is acceptable, provided there is proof the critter doesn’t awaken while paralyzed.
Maybe what I’m looking for is a distraction. A movie of an alpha squirrel displaying to claim my roof as his sole territory.
Well, I’ve done the relocation thing, with gray squirrels, even. You can buy the trap at Home Depot, and play voyageur in your very own attic. I think I ended up relocating three squirrels to the other side of town. I believe people there were very happy to see them.
You should dress up as an attactive female squirrel and lure him into trap. Then hit him on the head with a huge mallet.
Havahart trap baited with birdseed or…rat poison.
You don’t actually think the color of the squirrel makes a difference as to whether or not a trap will work do you? If you do, give up. The squirrel is going to outsmart you anyway.
Couldn’t you just tell him his services are no longer required?
First you find someone who sells bobcats. Then you bring said bobcat to your house, and give him the squirrel scent. After that…
Oh, you said humanely. I thought you said naturally. Bobcat=nature, right?
Several years ago, back East, we were plagued by great hordes of gray squirrels burying acorns all over our lawn, making a mess (they dig a hole and drop in the acorn, but stupidly scratch a little dirt into the hole, but don’t replace the grass divot.)
So, got out my trusty Havahart trap, used peanut butter for bait, and immediately started catching them.
I worked across the Hudson River, so figured I’d take the first one to work and turn it lose. I drove a VW Bug, so put the trap in the front trunk. When I got to the parking lot, I got out, opened the lid, took out the trap, opened it, and let the thing scooted out.
Then I noticed the parking attendant look at me with the strangest expression. He probably thought the squirrel was in a treadmil and was the motive power for my little VW. I still snicker about that.
Anyway, FYI, caught a whole mess of the critters, and eventually was squirrel-free for a long time.
Just find friend or relative who has a pump gun and let him kill that damned rodent.
It might be against the law in your state to relocate the squirrel because of the possibility of spreading rabies. It is in CT