Michael Cohen is called Donald Trump's personal lawyer, but really he's a "fixer" - a man who solves problems for the boss.It all came unstuck when investigators probed into hush money payments he made to a model and a porn star.He pleaded guilty to eight criminal counts, and announced he was happy to tell the truth to anyone who asked for it.So what information will he give up and should Trump be worried?Want to get in touch? Email russia@abc.net.au.