Click the big blue button in the top-right corner of the page and select Edit profile.
Click on the link Delete account in the window that opens.
Caution: When deleting your TeamViewer account, your entire account - including all the data it contains - will be permanently deleted. This includes all of the groups you own, and the computers and contacts inside them. This data cannot be recovered later!
Note: If your account belongs to a TeamViewer company profile, it may be that the link “Delete account” is not shown. In this case, you do not have permission to delete your account. You will need to contact the administrator of your TeamViewer company profile and ask them to delete your account for you via the User Management page.