Hi!

How can we disable Software Update Service from the Configuration Manager and remove the WSUS Server settings from the clients?

Thanks.

Deploy client settings to those devices with the setting Enable software updates on clients, in Software Updates, is set to No. That will wipe the settings delivered by ConfigMgr.

Also, if you don't want to use the software updates functionality of ConfigMgr at all, simply remove the software update point. That will also remove the ability to configure the software updates on clients, via ConfigMgr.