TOPIC: Import gedcom into existing family tree

I am using a genealogy program on my PC (Legacy) to extend and maintain my family tree.
Legacy produces (exports) a gedcom file (Gedcom 5.5.1) which is imported to Webtrees.
Before importing I have to edit the media-file part of the gedcom a bit - a very tedious job.
Then Import the gedcom file - which erases the exising genealogy data before importing.

It would be nice if I could export a gedcom file for the new/changed individuals from Legacy, edit this file a bit,
and then import it _into_ the existing webtree-tree without the existing genealogy data being destroyed.

Possible ?

> I have to edit the media-file part of the gedcom a bit - a very tedious job.

Edit how?

If you are just changing the folder names, then webtrees can do this for you automatically.

> Possible ?

If you are editing both systems at the same time - then no.

If you are only editing the tree in Legacy then why merge? Why not just overwrite the entire tree with the updated GEDCOM file.

Why I has to edit ?

Legacy sets "_PRIM Y" on all media.

If an individual has a Person-photo and Pictures of places, churches etc and/or Documents (pdf) it semms to impost nicely.
If an individual has no person-photo, but photo and/or other documents the church/place/document is presented in webtrees as the person-photo.

If I change "_PRIM Y" to "_PRIM N" on those individuals media it imports and displays nicely (silhouette as person-photo.