If you copy the existing Airnav directory somewhere safe so that you have a backup, then install 3.07 into its default separate directory, you can then copy the new ANRB.exe (rename the copy) into the original RB directory and create a new program object to run it.
That way the new and the old version will share all the already downloaded photos, log files, outlines etc. with very little risk of anything going wrong.
