Hi there, to delete an unwanted version of a dataset in your Library:
1. Go to the Library page and click the Version button associated with the dataset:

2. The Versions page for that dataset opens. Just click the "x" button to remove the unwanted version:

As a pro tip-- notice in the upper right corner of the page-- there is a "delete all versions" options that allows you to quickly remove all versions of a dataset... but proceed with caution :smile:
Hope this helps