Media, tags in a new.old package

Anki Help
1

Hi,
I have a folder containing over 34K notes. Some of them are with media. All of them have tags.
Unfortunately I can’t see the media and most of the tags are not shown correctly.
I already have some of them categorized personally. I have two questions:

  1. Is there a way that I can overwrite the missing media WITHOUT deleting the whole deck ?
  2. Is there a way to overwrite the tags ? so that the the notes available be tagged as the new package ?
    Thanks.