If you had installed WordPress via Softaculous, then you have to delete the CMS the same way. Otherwise you will have conflicts and bugs in Softaculous further on. If you had installed WordPress manually — read this manual.
- Log into cPanel.
- Under Software click Softaculous App Installer.
- Click Installations.
- Click on the red cross next to the website you want to remove.
- Click Remove Installation.
- Click OK.
Now you can reinstall WordPress or even install another CMS to your hosting.