How big of a tank is it and are you just resealing to be sure, or because its leaking?

We resealed my 180 gallon tank. It was leaking out of the front left area. It was alot of work to completely take off the pane of glass and remove all of the old silicone. Putting it back together wasnt nearly as hard. Make sure you clamp it well and let it sit for a few days at least, longer the better. My silicone is not perfect but it works and still looks pretty good. If your just resealing the inside, it wont be that bad. Just make sure you get all the old silicone out and then clean it with alcohol.