How does the Buddha subdue fear in MN4?
Good question! Not everyone finds this episode interesting - and yet it illustrates a very important point.
Buddha subdues his fear by bringing all of his attention to the present moment.

As I was staying there a deer came by, or a peacock snapped a twig, or the wind rustled the leaves. Then I thought, ‘Is this that fear and dread coming?’ Then I thought, ‘Why do I always meditate expecting that fear and terror to come? Why don’t I get rid of that fear and dread just as it comes, while remaining just as I am?’

Normally when we are afraid, our mind gets split. Half of it is in the present moment and another half runs to a hypothetical future, imagining the dreadful scenario. Buddha said, why do I always do that, why do I imagine things? Rather than worry about them why don't I focus on what I was doing?
This happens a lot to us. We imagine what our neighbors think about us, we imagine our audience judging us when giving a lecture, we imagine things lurking in the night when putting the trash can out for pickup. The more we worry about them the more we lose our ground and our connection with the real situation.
Instead if we can focus on doing what we started - which is what actually matters anyway - then we will not only stop experiencing fear, we will do better in terms of meeting an actual danger if it should ever come.