Terrain model with sketchup pro

Hi, I am working on a landscape model that has me totally perplexed, and I have no idea how to work on this model. I am a landscape architect, and still pretty new to Google Sketchup. I have the latest Pro version model.

So, the bottom image is basically the existing grade of a courtyard, with a sidewalk that is existing. The grade slopes basically from 0 inches up to 4 ft, but it is a cross diagonal slope. I used a method from someone that told me to create “toothpicks”. I shop spot elevations throughout the side, and the bottom image shows the existing grade. By the way, what you are also seeing on the bottom image is my attempt to drape my top plan onto the slope. So here is my issue. The top image is my plan from a dwg plan, that I converted over to sketch up. I need to match that plan with the sidewalks that meet the circlular image on the bottom. I will be sinking this image slightly, and using retaining walls, but, the patio surface on the top image is going to have to slope for drainage, and to meet existing sidewalk in the lower image. I wish I could delete the center part of the circular sidewalk, drop down my top image, but I need to change the plane or angle of the top image to meet the lower circular sidewalk image. I know this probably does not make sense, and I do not know if it is even possible to do what I am trying to accomplish. Thanks again everyone for your help.

Not much anyway.
Maybe better phrased and with less words.
I would like to help, but sorry, I just can’t.

I would like to delete the entire area in the lower image inside the sidewalks tht you see. I than need to drop the top image into this area, but change red and green axis of the top image. The pavilion is a group, that will remain at 90 degrees on the blue axis. Thank you.