Processes can, in the legal context, sometimes be interrelated with mechanisms which is why you might be getting it confused. Usually though, processes are a series of actions or mechanisms that bring some kind of result. It's a step by step kind of thing rather than just one mechanism or action in isolation.
Mechanisms - an instrument or framework
Take multilateral treaties as an example. The actual treaty is the mechanism of promoting world order whereas the process would be for example, the proposal of the treaty, then state parties considering whether to sign it or not, then signing it, then ratifying it etc.
Remedies - yes, in a way I guess they are outcomes. However, a more appropriate way of defining it may be the procedures in place to overcome or correct some kind of problem
Law reform is just the way in which law is changed eg: recommendations by law reform commissions or changing societal values may trigger law reform (changes to the law)
hope that helped
thxxx