Locked out by Upfront BUilder

Hi, I have just installed the Upfront Builder Plugin and have been immediately locked out of my super-admin access. When attempting to login I get the following "Sorry, you are not allowed to access this page." I have found a beta update in the forums @ https://premium.wpmudev.org/forums/topic/installed-upfront-update-and-get-this-message-sorry-you-are-not-allowed-to-access-this-page. However as I can no longer access my admin I do not know how to remove the plugin and install the new one. Please help...