Well... It's very easy! Simply go to the home page, https://youkast.com and "click" on the upload tab in the upper left corner or the large purple button near the middle of the page. Please see image below.
Simply visit https://youkast.com and in the upper right corner you will see a large purple button that says "Create account".
Click on the link (Button) and this will take you to the register page. Once there, fill in all required information and "click" Create a new account.
Once done you will be able to log into your YouKast.com Account.
If you created an account, all your videos will be saved in your admin area and you will be able to delete your videos. If you uploaded while anonymous you will not be able to access your video to delete it.
So... If you logged in while uploading your videos you will be able to delete them. First, login to your YouKast account. Once you log in... You will br brought to the home page. In the upper right corner, you will see a buttom called "My Videos". Click on "My Videos".
When you click on "My Videos", you will be brought to your video dashboard. Once there you will be able to see all your uploaded videos. On a video tile on the bottom right you will see a "Red Trashcan" Click on the "Red Trashcan to delete a video.