Hi Cookie,
I'd try the following.
New drawing
Import the symbol.
Turn on all classes
Edit Symbol 2d - Select all Zoom to selection - Cut
Exit Edit.
Edit Symbol 3d
Select all
Zoom to selection - Group (you are in Top/Plan View)
Move the group so that your preferred insertion point is at (0,0,0)
Delete any loci
Exit Edit
Edit Symbol 2d
Paste - Group and Move as above.
Exit
Rename - Import to your original file and give it a go.