Very, very nice job on removing the overflow!!! You are much braver than me using a chisel and hammer.
thank you i was so scared every swing i dont think ill every be that lucky again. the point chisel helped so it broke where i wanted it. the back was the worse but when i got it all the way to the silicone i was able to just get a razor behind it and slice it out. when my tank clears up ill take a pic of it and post it on here