I am new to Solidworks, coming from Unigraphics so its likely I'm doing something wrong in my order of operations.

So I am working with an assembly and I want to open a few solids from it, modify them, save them with a new name, then insert them back into the assembly.  The problem I am encountering is when I go to Insert them back in, they are not coming back into the assemblys position.  I have done a test to see the difference of "open part" and "open part in positoin" and both are being re-inserted out of position.  What am I doing wrong?

Thanks In advace.  I really appreciate the help!