Ernie1, you can't remove a channel/app if you currently have a subscription through Roku. You have to cancel the subscription first. Once you cancel it at https://my.roku.com or using the "Manage subscription" option the "Remove channel" option should appear. When you remove it, make sure you restart your Roku device from Settings->System or Settings->System->Power, as appropriate. Once you install it again, you should have access to the subscription through the end of its current period.
Because of issues like this, most people here would recommend you subscribe directly with the provider and not through Roku.