Hi, can someone help me with closing this section? 
It wasn’t meant to be at first but they requested this to be closed so it’s much easier to 3D print it…
thank you so much
jaztena-concept01-revised.skp (317.2 KB)
jaztena-concept01-revised.skp (317.2 KB)
Did you try using the rotate tool? If you attach a skp file, the experts can show you how.
It’s not clear to me what you mean by “closing this section”. Perhaps you could explain more? The area outlined in red in your image doesn’t have a complete boundary, so I don’t understand where the closing would go.
As is, there are issues in your model that will prevent it from being 3D printable. In general, to 3D print correctly, a SketchUp model must contain a single group or component that SketchUp recognizes as a solid. Nothing in your current model is a solid!
The most serious issue is that the groups have zero thickness. A printer can’t create something that has no thickness! SketchUp also won’t recognize something with zero thickness as a valid solid.
There is also a hole in the shape:
You have made two copies of the group rotated from each other and wrapped them in an outer group. Some printers will accept nested groups, but SketchUp will not recognize such a thing as a valid solid.
I’m going to armchair quarterback this one because I’m on my phone right now and have just looked at your file with the viewer app.
First thing would be to close that hole.
Next, install the joint push pull and solid inspector extensions.
Try thickening one of the shell shapes with JPP.
If that works, dance a jig because you’ll have hopefully made it into a solid. Multiple solids can be united using solid tools, built into your SU pro.
At each stage try using solid inspector- this can tell you if you have a valid Sketchup solid and if not, help you identify the reasons why.
I would recommend scaling everything up a hundred or thousand times as this can help with the tiny polygons that need to be created during the solid tools processing. You’ll see this described on this site as ‘The Dave Method’ after Dave Richards, one of the SU genii here.
Scale back down when you have a valid solid shape that you like and it will most likely be 3D printable.
This is not for the faint hearted and I wish you success. It will feel amazing when it works!