The side trim is fairly sturdy, you should be able to pop it off its clips without damaging it. Some of the clips that hold it on may not survive though. New clips are very cheep, and available from most of the usual TR7 parts suppliers.
I have no usefull info on the windshield trim. I tried to remove it first when I was taking my windshield out while stipping my car. The windshield turned out to not be in very well, so the entire thing popped out with the trim still on it...