Stepplot y-axis names

I have a stepplot that looks like this:

The system output responses are labelled like 'To: name' Is there any way to either remove these entirely and to also just remove the 'To:'

I want to have a subplot like this

So I only need one set of y-axis labels to represent both.

This is a stepplot (timeoptions) and I cannot work out what I need to change and what format it needs to be.