It bothers me that the Big Guy (who is dying, but more slowly than expected) is such ***** that it's unlikely he's ever handled a firearm.
Many DUmmies who have failed to overdose have ended their miserable existence with powder and lead, but that route is unlikely to be open to the Big Guy (who is dying, but more slowly than expected), since he'd never be able to figure out how to load the weapon.
But I'm happy to offer a suggestion.
For many years, the Big Guy (who is dying, but more slowly than expected) worked in the Omaha sewage treatment plant. His job was to ride in a little catbird seat that traversed back and forth over the huge vat of incoming raw sewage. He was given a long stick with a nail in one end, and his responsibility was to fish used condoms out of the sewage before they could clog up the treatment equipment. Over the years, he became one of the top rubber snaggers in the entire department, when not off work with some phantom injury, or sleeping in the catbird seat (which he often did despite the staggering odor percolating up out of the vat).
My suggestion is that he go back to the sewer plant and explain to his former co-workers that he'd like to take one last trip in the catbird seat, for old times' sake. Then, while far out in the center of the huge vat, over ten feet of bubbling, roiling, rippling sewage, he should just take a dive. There could be no more fitting end for a DUmpmonkey.