[bugwelle]

i use mediaelch to scrape shows using tvdb mainly to add fanart.
i've set kodi to scrape with tvdb.

now if i want to change the fanart with mediaelch what do i need to do so that kodi uses the new fanart?

Have you saved the fanart to disc, i.e. does it exist next to your movie files?
What Kodi version do you use? Have you set the same version in MediaElch's settings -> Kodi Tab -> Kodi Version?

do i need mediaelch to scrape individual episodes or can kodi do that?
what is the proper way to have mediaelch scrape a new series i add to my collection and then have kodi update individual episodes that i later add?

Personally, I use MediaElch to scrape all episodes. Because I set "Local NFO file" in Kodi, I don't know if Kodi would load new episode details.