Well there are a lot of things to consider to hack an account.
1. You need to be smart.
2. You need to be convincing.
3. You must be unknown.
if you know all of this,then you can hack an account.
then try to figure Username and password logger into your email (e.g. like making a scam site) or hack the main database of the server..
dont ask me how to do this because i dont want to destroy other's rights. try google on how to but be careful always!