The most typical kind of mane mat on a horse is where two or more sections twist themselves together usually forming some type of dreadlock towards the bottom of the mane. Here are some step-by-step to detangle a mane.
To warm up hardened coconut oil, just pry a chunk of it out and then rub it in the palm of your hand. As the rubbing motion generates heat, the coconut oil will return to a liquid state.
Work this through and start detangling the mane from the bottom up