How to delete iCloud info

Delete the items on your device. Since iCloud reflects and transmits to other devices what you do on one then the data will be deleted in iCloud too. If it is data you wish to retain then make sure you have an independent backup. If you only wish to delete the copy in iCloud, disable iCloud syncing on your devices then log into iCloud.com with a web browser and delete the data using the apps there. Do not turn on syncing again or else it will all end up back on there again.

Change which apps sync and store data with iCloud - Apple Support