You probably can’t. That may be a job for a professional.
Are you stoned?
Ninja’d
The hornets have turned inside out.
Yellow jackets die over the winter, and don’t rebuild the same nest site. (At least, they do in my climate, dunno about that of your brother.) We had a similar situation, and decided to just wait them out. In due time, they died, and we forget about it. A couple years later we had some construction done, and a carpenter opened up that wall. “Did you know you had an ENORMOUS wasp nest there?”, he asked us. “Yup”.
Ten feet is close enough that you will see a lot of wasps, but it’s far enough that just walking by won’t alarm them, and with modest care, no one will get stung.
I used to have a wasp problem. My apartment looked back on a nursery lot, and I would wake up of a summer afternoon (I worked graveyard) to the fragrance of the 25’ pile of shit and the ticking sound of wasps beating their faces on my windows.trying to get out. One day, on arriving home, I observed a wasp flying up to the eave and entering a tiny hole below a truss stud. after that, I noticed a gap in the ceiling tiles, which was easily fixed with a bit of spackle and lo no more wasps.
I know about the dying part, but what about their eggs? Don’t they hatch and continue the nest?
I did a bunch of research when we had the huge nest, and no, a new queen hibernates underground and will start a new nest elsewhere.
I found a lot of sites that said things like:
if you had a yellow jacket or hornet nest last year, you don’t need to worry about that nest. Yellow jackets and hornets do NOT reuse the same nest the following year.
While nests may last through winter if built in sheltered areas, they will not be used again.
An exception to the normal life cycle occurs in warmer climates that typically do not experience prolonged temperatures below freezing, such as Florida, Texas, etc. Nests can continue to grow in these warmer climates for more than a season
Mine certainly did die off when it got cold, and was not reused.
We didn’t bother, because ours was actually on the roof and hard to get to, but if you have a nest in a wall, look to see where the wasps are getting in and out, and caulk those holes over the winter.
You guys already have told me two things on different subjects that I didn’t know, and it’s only 6:45 am! That’s why I luv’s ya’!! 
Around here, the queen stops laying eggs in September or early October. Yellowjacket behavior, AIUI, involves the adults going out and catching insect prey, which they bring back to the nest and feed to the larva. The larva ooze sweet juice that the adults lick up for their sustenance and energy. When there are no longer larva in the nest, the adults go hungry: they cannot eat insects because of their slender wasp waists, though which only liquids can pass. Hence, in the fall, yellowjackets become real assholes because of hunger and impending death.
I sympathize because, considering their bleak circumstances, I think I would, too. LOL
A key thing to aim for with destroying pestilential bee/yellow jacket/wasp nests is using an environmentally friendly technique.
Liquid nitrogen, boiling water and the like may sterilize a patch of ground (including killing beneficial organisms) but such effects are limited and temporary. Pouring certain substances (i.e. battery acid, motor oil, bleach, ammonia etc.) into ground nests or using caulk/insulation would create a mess, and disposal of contaminated soil in landfills isn’t an environmentally great choice.
The only bee/wasp-like creatures I’ve had to dispose of here are &*@#! carpenter bees, which are large, annoying (don’t appreciate their hovering and dive-bombing behavior even though actual attack does not occur) and excavate holes into your siding and wood trim. Diligent application of pyrethroid bee sprays eventually took care of the population this past spring, though I anticipate the battle will have to be renewed in '23.
I wish I had a giant yellow jacket nest to wipe out. 
I could’ve helped you out a couple months ago.