I want to change to this as I find this easy to work with..... My partner owns both the domain name and has paid for the hosting, problem being he does not have any idea who with or anything. Where the hell do I start

Apply to bravenet to see if they can take on the domain names, You should receive a communication from the current holder requesting confirmation. They will probably want a transfer payment, but at least you will get things rolling. In the meantime try to get copies of your web pages stored locally, as when the domain name moves you will lose the current site.