You should be aware that a landscaping project involving redoing or reconfiguring hardscapes - stairways, landings, paths, retaining or rock walls - is going to be pricey and unless one is a very skilled and experienced DIY'er, not something easily accomplished by a homeowner. In my area, you would be looking at a $10-15K project, perhaps more, depending on materials selected..

Given the slopes, consider paying for a professional design plan, then get job quotes. As you lengthen the stair run (likely by incorporating intermittent landings) you want to be sure the slope and stair heights mesh in order to create an access to the front yard and not create a runoff issue.

How do you want to use the front yard? The yard slope limits its usefulness. Have you considered leaving the steps/rocks as is and converting the front yard from grass to plantings?

The most obvious plan is to make a big landing where the stairs meet the stone wall, about the space of the last 4 steps. Then, remove the shrub (you can always transplant it). You might need to remove some of the rocks, because the new landing will need a longer run.

You can game out the options. It's worth noting, however, that if you need a professional to move rocks, having a much different stairs (more landings, longer, less steep) might not be that much more expensive than the minimum. That's why it's worth talking to a landscape designer.