For carers, this is how I approach a PTSD sufferers forceful self. A sufferer is typically very stuck in their ways, good or bad. If you try and fix them, the information just won't sink in. If you want them to change, don't give them just your opinion, instead, give them various options, one of which is yours obviously, though do not state which. Simply ask them, "If what your doing is working for you so well, then why do you feel like x?" is a very good question to a sufferer. It is about not fixing them, but pushing them in a direction in which they will think about options and most likely take one of those options. You can call it a form of manipulation if you like, but at the end of the day the choice is theirs to which option they take. That is how you open a sufferers eyes to different ways. The moment you try and force your opinion down their throat they will only resist harder, so instead you add your opinion in with other methods, ways, whatever your opinion is about, then you present options to the sufferer in which they choose. Then, if your option (opinion) is wrong, they won't dig in harder, yet may feel another option you presented them is good for them, better than what they are using now, and adopt that instead.

Opinions = personal options.