Since I have been down this route and am still struggling at its throat.

The only way is to "forcibly" get him OUT with family, friends and cow-orkers.

Even people that really annoy him (but seem to like him) really help in this regard. Antagonists rule in the arena on that (hot button pushers and the like)

Drag him along and do not accept NO as an answer. With one exception, if he violently refuses, no sense getting hurt over someone elses problems.

If you go do something, anything, even just go for a ride, shopping @ $LOCAL_SUPERMARKET_NOT_WALMART. Does he like NASCAR? If so, get him to one of the places that does simulated NASCAR rides. Bowling... yes get him in a League. He needs fill time activities... OUTSIDE of the home. Home is his "safe but bad for him because he can sit-N-mull" place. Stewing and stirring up the crap from the bottom of the cauldron never helps.

His family *HAS* to also get him out. Period. Even though he hates work... does he have ANYONE there that can prod him along? Invite him out to Lunches, include him in extra-cirricular stuff. Does the place have a Bowling Team or an "User Groups" or anything similar.

Just fricking trapsing over to a friend's house for the evening is better than sitting home.

It takes getting out, interacting, seeing the world isn't so damn grey. Taken me over 10 years to get from really really darkly depressed, to almost considered rehabilitated (yeah, no such thing). Took a family that cares, friends that helped, cow-orkers that antagonized that crap out of me.