Although many of people would like to delete Trump's Twitter account here is small step by step tutorial how to delete your own Twitter account.
If you want to preserve your data you can download your Twitter archive before erasing your account. Simply browse to Settings > Your Twitter archive and click Request your archive. Twitter will email you a link when the file is ready to be downloaded; this process might take up to a couple of days.
After you download your archive you can delete your Twitter account.
Open Twitter.com and log in to your account (you can only delete accounts from the web, not from mobile phones).
Go to your account settings by clicking on your profile picture in the top-right corner and selecting from the pull-down menu.
Click "Deactivate my account." It's written in small type the bottom of the page.
Click the Deactivate button. It will ask you to enter your password to confirm that you really want to delete your Twitter account.
And that is all. You Twitter account is deleted.