Here's how it went...
1) I cut away the silicone as much as possible with razor knife on both inside and outside of the tank bottom. I laid the tank on its side to do this from the inside.
2) The bottom pieces that were small came off easy, I got most of them off when the trim came off. The two ends that were large did not want to budge.
3) I tried getting the razor knife to cut between the bottom and the sides but it wouldn't go. So I took one of those 1x2 stakes and pried 8-O on the bottom. I could see the silicone start to release by allowing bubbles under the glass. I just kept steady pressure... not too much though. Then I could start to hear the silicone give way. It was a slow process but keeping the steady pressure was the key.
Here is what I have now. This is a small chip in the front side:
And here is one in the back side opposite end:
And overall shot...
Gotta go fire up the pit.. BBQ time!