Lowering DT water level question

[Ryancw]

my tank has been up and running now for two and a half years, during that time I've chosen to ignore the fact that the water level is far too high and so close to the euro brace that underneath it collects water and salt creep.
Has anyone ever attempted to dremel their overflow teeth lower while the tank is still operational or would significant draining be the safer route?

I figured if i ran socks as i normally do.. any acrylic would collect there for easy removal when im done. any opinons?


Thanks