Saving NF activity logs to disc or hard drive

How can I save the NF activity logs for children on to disc or hard drive. I need to ensure that I have a back up of all logs for an indefinite time, just in case something happens and cannot retrieve info from website or app. Also is there a plan to be able to see mms messages any time in future. That is a lot of stuff getting by me because we can't view actual content of mms. Thanks.