[mythtv-users] How to replace a .nuv file with edited one

[Robin at Home]

With the use of nuvexport I cut out the part of the recordings I don't need. 
It cuts
out the parts which I have marked within Mythtv and is stored in the 
cutlist. This export
file then gets stored on another place.

Now I would like to replace my original recording with this exported file to 
save up
space on my harddisk.

I can just copy the exported file over the original file (so it gets the 
same name) but
then the information in the database is out of sync with the file. So it 
actually thinks
e.g. that the length is still as it was while it is maybe half.

How do I replace a .nuv file correctly ?