If you're looking to uninstall a specific update, you'll find that it's quite tedicious to do this via the GUI. It shows an endless list of updates and it's very difficult to find the right one through its KB number. Fortunately, you can also uninstall updates from the command line, by specifying only its KB number, which is veeerry useful indeed.
Open an elevated command prompt and run the following command to uninstall an update by its KB number:
wusa /uninstall /kb:3035583
Replace the number with the number of the KB you wish to uninstall (the line above would uninstall the Windows 10 Upgrade prompt).
You can also add additional parameters:
wusa /uninstall /kb:3035583 /quiet /norestart
This would uninstall the Windows 10 Upgrade prompt without prompting you for it (/quiet) and without prompting for a restart after the uninstallation (/norestart).
Note that if you want to avoid the update from being reinstalled, you need to hide it from Windows Update after the uninstall is completed (you may have to reboot as well before the update is visible in Windows Update).