this is where he cut the rim and his info from that thread:
i did this over two weeks ago and no sign of stress.
First you need to run a razor blade or sharp scraper all around the rim to cut the silicone. Next i took a small hacksaw and cut the rim into two pieces. Take care not to hit the glass. When you start to get close to cutting through the plastic pry the rim away from the glass to make it easier to cut. yes it will put shavings in the water but i ran some filter floss to remove it. After the rim is cut in to the pieces you need to pry and lift the rim towards the inside of the tank. I will be tough at first but it does come off. Just need to get through the rest of the silicone. Once off use the razor blade to remove the rest of the silicone.
i did this over two weeks ago and no sign of stress.
First you need to run a razor blade or sharp scraper all around the rim to cut the silicone. Next i took a small hacksaw and cut the rim into two pieces. Take care not to hit the glass. When you start to get close to cutting through the plastic pry the rim away from the glass to make it easier to cut. yes it will put shavings in the water but i ran some filter floss to remove it. After the rim is cut in to the pieces you need to pry and lift the rim towards the inside of the tank. I will be tough at first but it does come off. Just need to get through the rest of the silicone. Once off use the razor blade to remove the rest of the silicone.