Delete old submissions to free up space for new

How do we delete old forms?  My organization would like to delete old submissions to free up space for new.  Please advise!

To delete submissions, please see the guide below:

How-to-Delete-Form-Submission-Data

Note that storage space is mostly consumed by the uploaded files on your form, so if you wish to free up space, you need to delete submissions that has uploaded files.

As per checking of your account, it seems that you are instead referring to submission storage. Just simply follow the instructions in the guide shared earlier.