How to unstall my cloud app and reinstall

Recently I resett my passport wireless,and did the settings again as new one,but my ,mycloud app does not response,asking me the email addres and password,i did try all my emails and passwords,but always rejects. So i thought to uninstall my cloud app and reinstall it.Please let me know that it is the god idea and how to do it, Thanks.

You uninstall the app like you would any other app on your mobile device and then re-install it.