Sorry to say bud, but your chances are almost zero, or zero entirely, like I believe some other forum members have said, trust system on this forum is not in the hands of the admin, the system is completely decentralized, even though the forum itself is centralized.
You will just have to learn to live with those negative tags because, those who gave it are not user's that can easily change their minds on something they have already made up their mind on. So i will just suggest that you accept what you yourself have brought upon yourself and move on.

This forum is not like just any other forum out there, here, if you must make any headways, you must understand the rules, understand what's forbidden and stay away from such, its as simple as that, but as long as you've gone against the rules and earned negative tags for yourself, its hard to get it off, and yours case here is an example which also should teach others with intentions as yours, to desist from doing what is wrong.