Massimo,
You need to (1) do a "Save As..." operation on the VI with all of its parent VIs in memory, then (2) save the parent VIs, and finally (3) you will need to delete the old VI.
I have created a LabVIEW add-on which automates the last step of deleting the original VI. This add-on creates an option in your pull-down menu called
File >> Move/Rename VI As... It will prompt you for the new name/location of your VI, it will save it to that location, and finally delete the original. Make sure that you have all the parent VIs in memory, so that they "see" their subVI being moved/saved to a new location and then save the parents afterward.
To install the attached tool, put the LLB file in the following location (You will have to crea
te the "wizard" folder, if there isn't already one there):
/wizard/Move_Rename_VI.llbGood luck,
Jim