How can I clear my history

I am about to reach my history limit, but I don;t need the storage.  How can I clear this?

You have reached your monthly submissions limit, it will reset tomorrow, since the counter resets the first day of each months.

On regards of the storage, a free account allows you to store up to 500 submissions in your account. You can free up space by deleting submissions: https://www.jotform.com/help/377-How-to-Delete-Form-Submission-Data 

Let us know if you need anything else, we will be glad to assist you.