Sorry, let me try and explain:
AOL have their own software, pictured below
When you open the software you have to login to your account, which uses the same details as your @aol.com. It allows me to log into the AOL software and view my email via the 'Read button' (top left on picture above). However, if I try to access my email via the web, or iPhone mail section etc it says my password is incorrect
To change your password, you have to log into 'My AOL', when I try to log into that, it says the password is incorrect