Emailed Antec and got a quick responce:
Comment: I have a number of ways to pop that out, depending on what I have at
hand. Here's a couple:
You can take a ruler and insert it into the 3.5 bay from inside the case and pop
the cover off that way. This is the easiest way I know.
You can take a small screwdriver and insert it into the upper gap around the
cover and gently roll it to the side (don't 'pry' or you might mar the front
plastic) until the faceplate comes loose.
...........................
Tried Antec's suggesttion of inserting with a steel straight edge from inside the case -
got the Cover to bow but it still would not come off.
Finally got the '3.5" Drive Bay Cover' off.

- I took the whole front face (including door) off.
Thanks for looking and thank you, Antec for your quick reply.