My question is what does one need to do to have the trust removed?
Depends on what exactly you did. 
Is there a probation period, are trend I can go read to get clarification?
No.I have tried to go through the forum but i cant find anything substantial.
Trust ratings are not really a matter of the forum (Meta), but rather Reputation section. These get left independently by forum users.I see it's all about reputation and like also a respect of one person to another user, Because some campaign really strict with negative trust and forbidden to join with their if you have negative, some also doesn't care as long as you do the right thing, Thank for the info.