How Do I Unblock People?

I have someone on my Twitter that I know I have blocked, but all is good now and I am wanting to unblock that person. I cant for the life of me seem to find the settings / page in my account to do this. I have done it before once, a long time ago, but cant remember how I done it. Can someone help me out please by telling me how to do it. Thanks!

See original post by Sean101