Use  Forms Mode (click on Forms in the upper right corner) to see a list of all the forms in your portfolio.  Find the Wage and Tax Statement you want to delete.  These are W-2s so in the list, it will say  !Form W-2 (company name) (Not Done).  Click on the W-2, then use the Delete Form button at the bottom of the page, see image attached.

You can also type   w2   into the search bar and click Find.  Then use the Jump to link and delete the W-2s from the W-2 Summary.