Q: How can I reassign a specific character to another key of my keyboard...

Specifically, the t key on the built in keyboard of my mackbook pro stopped working completely. It used to work if I pressed it hard but now won't respond. All other keys work perfectly so I assume it's something wrong with this specific key.

Is there a way I can make another key type the letter t when I press it? For example so that pressing the ~ key will give type a "t" instead of a "~" (I don't use that key so it wouldn't be a problem for me...)

Or how do I check the t key without damaging it?