Imported part/assembly

Hi all, I have this imported part/assembly. It came in with on of the parts for the assembly located in the wrong location. I can't seem to find a way to move the part to the correct location. Does anyone know how to make that change in an imported assembly. I tried opening the imported assy 1554N.stp but it won't open. I tried RMB to open the part 1554N-P, but it won't open either. Anybody?

Thank you for your help in advance.

Daniel

SolidworksImport/export