Editing imported STL files. (Geometry mayhem?)

SketchUp 3D Printing
1

I’ve imported a few files, and some I have had joy with adjusting, however I’m now having trouble with this model.
Once imported, it is an utter mess of lines, which makes it near impossible to edit.
Here is a picture once imported.

1624×733 348 KB

I’ve added an extension called cleanup, which then leaves me with this

1775×700 173 KB

However, I still can’t edit the file due to the mess around the sides, or edges (like removing some parts). Is there any way to clean these as well?
I am a newbie to Sketchup, so I might be missing something obvious, but for the life of me, I’m stumped.

Many thanks
Steve

2

Make the upper face a group then delete the rest of the geometry then get inside the group and push pull it.

3

Took a little while to get there, but I found it! Massive help and definitely makes it easier to change.
Thanks bud. :smile: