I promised a while back to post my findings on what it takes to change the
operating limitations to allow night flying. I called the EAA first and they
told me that what I have to do would be spelled out in my existing operating
limitations. I hadn't thought to look there first because I knew it said day
VFR and thought it would be left at that. The EAA guy said that there should
be something there and what it said depends on the original inspector and how
long ago they were done. He said it could say that I need to notify the FAA,
just make a logbook entry, or something else. Sure enough my limitations said
"Unless appropriately equipped for night and/or instrument flight in accordance
with FAR section 91.205, this aircraft shall be operated day VFR only." So in
my case the operating limitations don't need to be changed, I just need to
appropriately equip the plane and make a logbook entry and I am good to go.
The FSDO concured.