pm box full - how can I archive them?

[slast]

Title says it all - I have 137 pms in total, I don't want to delete them completely, but it says the limit is 150, and I haven't found anything useful in a quick search here.

[Saab Dastard]

Go to Inbox. Right at the bottom you will find:
Download all Private Messages as:
XML | CSV | Text
Fill your boots.

[slast]

Thank you!