How do I tell this to my parents?

Well you see my parents signed me up for this summer long twice a week ice skating thing. Before that I was doing a half hour of skating once a week with a friend. That was good enough because I am not into skating, in fact I dread it most times. This one is an hour long. But it was fun with my friend and our instructor. It’s RIDICULOUSLY expensive like 80 dollars a session and its too much! I really don’t understand why we’re doing this as we need the money for more important things. I really don’t care all that much about material things as they fade away or get lost really fast and I dont even notice.

I really dont want this stuff and these lessons. I want to spend more time on my guitar and really none on skating. I appreciate this but I dont see how were affording it. Also they signed me up first. They started talking about it and I didnt know how to say no to it but I didnt say yes either. I’m very tired of it and I’m not even competitive, Im recreational at the most and no one puts that much time and money into recreational skating! How do I tell them I’d rather stick to once a week?