Great advices too from @Chris_Atkinson and @G_W_Albrecht . One important note though...whatever you do, do NOT delete anything from /opt/CPda directory, because if you do and files related to older jumbos are gone, you will never be able to install jumbo 79. I had customer do that before in R80.40, but their saving grace was that I had a lab with exact same jumbo they deleted, so it was easy to fix. Its totally safe to delete from /var/log/CPda/repository.
Hope Radius auth issue is fixed in take 79.