So after copying there will be 2 Folders: 1 named "setimages" one named "FirstSet" (or shall FirstSet be copied within folder setimages).
The second. Currently inside your Lackey plugins folder you should see the following folder structure
Redemption-->sets-->setimages-->FirstSet
The cards images in the zip file should replace the cards in the folder above.
Some question regarding imagery: Some of the cards are lacking pictures. Can one replace them by its own?
This is and issue that I am still trying to resolve. It would help if someone could send me a list of cards with missing/mangled images.
Another question: I've just received a Disciples Expansion pack with "Stolen Blessing" but this card has no special ability on it. Within deck editor I only found a version with special ability. Are there any cards missing within deck editor?
Yes. I did not add error cards into the deck editor--which explains the Stolen Blessings with no SA. I also did not work at including any of the variant arts (e.g., left facing vs. right facing Abimelech). Lastly, although I have UL and L listed for some of the early cards, I do not believe any of these has the original limited art.