Hello,
We had a FAS8060 that we performed a controller replacement on and it certainly didn't take 3hrs. The 8080 is a bit easier (and less scary) since the two controller modules are physically separated and don't share the chassis for their power-supply redundancy.
Here's your KB for doing the replacement:
https://library.netapp.com/ecm/ecm_download_file/ECMP1199896
Luckily there's no messing around with disk ownership/etc like in the old days. The disks will get automatically assigned to the new SN# (i.e. new controller).
Hope that helps. Give a holler if you have any questions with specifics for the controller-swap. The previous replacement is still pretty fresh in my memory banks.
Good luck!
Chris