1. Activate Developer Mode.

2. Go to the Website Application.

3. Under the Configuration Menu at the Top click on Websites.

4. From the list of websites, select the one you need to delete by marking the check box to the left of the name.

5. In the center menu for the list click the gear icon and select delete.

Hope this helps!

I did it with sql, with this query
update product_pricelist set selectable='False' where id=1;
Then I deactivated the website of the products where I had them related and after that it let me delete the website. It's awkward, unconventional, insecure, you can make human error, but it works. I hope it works for you, and yes, you need a tool to delete websites, although I think that unpublishing them already works.

Yah it is working

Very poor customer support.