How to Archive an old device and remove it's 'offline' status

Hello everyone,

I’m trying to figure out how to Archive an old device but I’m having trouble finding documentation or forum posts regarding this issue. We have some old devices with graphing data that we would like to preserve but we don’t want these devices to show as ‘offline’. I know I can disable polling and alerting but this doesn’t prevent them from showing as ‘offline’ on our list of devices. Has anyone found a way to do this?

Thank you in advance and I apologize if this has been posted before, for I haven’t found any posts similar to this but I may not being use the correct key words.