They 'vote' the people who don't show up to vote. In the old days of punch cards it was don't by taking stacks of cards, putting an ice pick over the chad area to be punched and hitting it with a hammer.
It's easy to stop this type of voter fraud: Put a camera outside the polling places ( cheating is usually done in black neighborhoods) and count the people who go in to vote.
If a thousand more are 'voted' than went in, dems are cheating.
Dems don't vote the dead intentionally - the dead's cards are just swept up with the people who didn't show up to vote... (I don't know how they do it with paperless systems - but I'm sure they're still voting the people who don't show up)