Change other users' avatar

Is there a way for me, the admin, to change other users’ (subscribers) avatars??

Do I have to use a plugin? If so, which one. WP User Avatar only works when activated. To save memory, I’d like to be able to activate the plugin, change the avatar and then deactivate the plugin and keep the avatar.

If not, is there a way built into WordPress to change a user’s avatar? If not, can you think about including this in future updates?

Thank you