How seal overflow?

[Dnraiders]

I had the silicone on my internal over let go. I need to reseal the whole side and one side of the bottom seam. I know that the ideal way is to drain the tank and reseal the internal overflow Has anybody done this without draining the tank?
Thanks

 

[Schwabie33]

Is it possible to get the water level below the overflow line and do it from the inside? Keep in mind most silicone have a couple day drying periods.

If it was my tank, as much as it would suck I would set up another tank to transfer livestock into to fix the current issue, but I'm OCD about stuff like this.

 

[cromag27]

Silicone takes at least a week to fully cure.