In the first photo that is black and white, I started off by changing the exposure.  After that the photo was very plain and boring.  I changed the increase to a good amount to +70. I also adjusted the whites and the blacks.  After all that I still wanted a greater contrast so I changed the tone curve to a strong contrast.

On the Split tone photo after changing to greyscale  I only made a few more changes.  I moved the highlights hue just a little.  I wanted to adjust mainly the shadows which I did in my final step.