If you find yourself in the unfortunate position of facing dismissal or expulsion from your college or university, depends at what stage of the process that you're at in terms of what's going to be appropriate moving forward. If you've already been found responsible, if you're at the appeal stage, it would be, say a matter of potentially import appealing the outcome and also the sanction itself, arguing that it's a disproportion or unfair sanction and providing mitigating information as to why it should be a lesser sanction.
If you find that say the conduct office or the other people involved in the matter are suggesting an outcome that would say, included dismissed or expulsion steps could be taken to try to have that the matter addressed. Otherwise, having an experienced attorney advisor is going to be your best ally.
They could potentially intercede on one's behalf, whether it's with the conduct office, or with the school's attorney, the school's Office of General Counsel. It will depend on where the case stands and in terms of what would need to be done, but you need to have an experienced attorney advisor in your corner from as early as possible in the process to help you understand and navigate the process.