Q: How do you kick a team out of a conference?
A: It's pretty hard to borderline impossible
The only way to effectively do it is for a critical mass of schools to leave the conference and create a new one - essentially what the MWC did to the WAC.
The above comments are merely a parameter to keep in mind when thinking about the following:
What, if anything, does the B1G do in response to this (presuming it happens)?
1. Nothing (note: never discount this as a possible course of action)
2. Go after... someone?
Other than KU, I don't think there's another obvious "fit" for the B1G in what would be left of the B12.
Could they try and swing for a disgruntled Mizzou? (KU + MU could be a reasonable add)
Would they swallow their pride and slum it with ISU?
Would they pitch CU? (CU + KU could also be a reasonable add from their perspective - but, I think we'd have to give up on CU football ever being relevant again as we'd be so cut off from our recruiting grounds that we'd be well and truly ****ed)
The power move would be for a large fraction of the B1G to join with a large fraction of the Pac-12 and create a new super conference, leaving several of the other schools behind. (Note: this won't happen.)
Or, just rethink the whole thing, merge with the P12 and instead of even trying to create "fair" pods or divisions or whatever, create a tiered relegation system within the conference. There are Champions West and Champions East divisions and Also Rans West and East divisions, the two lower division "champions" move up the next season, and the bottom dwellers drop down. You want intense interest in games between non-ranked teams late in the season? Imagine Michigan and Northwestern meeting with relegation on the line, or... CU and NU meeting with promotion on the line? (Note: this won't happen either)