How do I sign out of iCloud on other devices

Hello aviance,

Upon careful reading of what you ask it seems you want to sign out of iCloud on a "other device" you do not have with you, in other words, remotely. The document Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac only tells you how to sign out on a device you have in-hand.

If you wish to stop a device you do not have with you from being signed into iCloud I think the only way to do that would be to remotely erase the device. This document tells you how to do that. Erase a device in Find My iPhone on iCloud.com - Apple Support

See the article Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac - Apple Support