removal of glass inserts

I recently received a 90 gallon custom tank. (was built a salt water
tank.) but I want to use it as a fresh water.. Problem is their are
several inserts of glass (mostly siliconed on) I need a way to remove
them ( was going to try using a razor type blade to cut the silicone,
but several of the pieces are very long.. and not a lot of space to
get between both pieces of glass. So any ideas would be greatly
appreciated.

thanks

amber dee