No proportion, hypothetically give ALL the votes to candidate B, then to candidate C, and so on. If none of those hypoithetical arrangements affect the outcome, the election was valid.
If the number of votes/delegates obtained by an ineligible candidate affects the booty due to somebody else, the only way to figure out where they belong is a do-over. The election is invalid.
The person suing doesn't have to prove they will win the do-over. All they have to prove is that the results of the contest aren't valid.
If Fiorina or Gilmore was found ineligible, no do-over. If Trump was found ineligible, do-over.
Go for it. Let us know how it works.