Restoring a compacted in Outlook Express

Went to back up a station for a wipe and re-install as the I was moving to a better OS. I have a bunch of messages in inbox under Outlook Express and I want to back them up and restore them after.

I read MS Help and it said to compact the folderto .DBX records and back them up. My issue is how do I restore them. I have tried importing but it doesn’t pull them in.

Is there a better way to back up? Or am I missing something on the restore?