This will unlock all your Image-Line products, not just FL Studio.
Enter your Image-Line account email and password and click Unlock products. This does not delete any of your personal files, it just replaces program files. Normally this will install over the existing installation. The FL Studio installer includes most plugins in native format, so no need to download them all. If you are updating, make sure not to start FL Studio until after you install the new version.
Update, upgrade, reinstall or uninstall FL Studio & plugins