Need help removing ambiguity from grammar
In your attempt put $T\rightarrow UV \ \bracevert\  V\  \bracevert\  [E]$ instead of $T\rightarrow E$. 

The idea is not to just replace symbols arbitrarily, but replace in such a way that it's derivations are a subset of possible derivations (which should be unambiguous).

And you can also use the procedure prescribed in textbooks or in Jonathan's answer in https://stackoverflow.com/questions/3106195/converting-ambiguous-grammar-to-unambiguous to remove ambiguity (unless the language in inherently ambiguous). I like Jonathan Leffler's answers because he gives lot of detail as well as intuition behind answers.