Firstly, Congrats on your trade!!!
Time to check the company website, your broker or contact the company to find out where they are not being traded (if at all)
Hopefully it will not be a big deal to be able to close out through your broker as most brokers that focus on traders offer BB and Pink.
Depending on the cost per share and the commissions you may end up with a large transaction component in your cost.
Best of luck to you