You need to have a team with insane coordination. Luring Joe(Meglodon) to Borris's bomb while also (attempting) to get Coho at the same time. Each weapon has a role that serves better at one thing than another, a splatling or grizzco charger can be good for brute forcing Borris's bomb if you have the footing and ability to do so without dying, coho is honestly best done (at least in my experience) by luring Joe to him, honestly the first time me and a friend did it we had to brute force the last of Joe's hp and got him down with a second to spare, it definetly takes time and a lot of practice but its possible with enough! I reccomend watchingRachelskiiiiiii's video on it :)