I have a sketchup file from a client but need to transfer it to SW to change some items and then make an STL for 3D printing.
I have a sketchup file from a client but need to transfer it to SW to change some items and then make an STL for 3D printing.
You would need to use sketchup to export it to a file format that Solidworks can import.
Using SketchUp Data with Other Modeling Programs or Tools | SketchUp Knowledge Base
If you can't do that, then either google search an online converter or contact your client and ask them to export it into a format you can use. (probably DXF or DWG).