First, they’d make sure that the voter rolls were full of ineligible voters. Deceased people, non-citizens, and people who have moved out of state would not be purged from the rolls, and there would be no mechanism in place to purge those ineligible voters.
Further, they wouldn’t have any preemptive check to ensure that only eligible voters registered in the first place. For instance, you can’t get a job in this country without showing a passport, birth certificate, or green card for a standard I-9 form. This ensures that only people eligible to legally work here get a job. There is no such citizen check when you register to vote. It’s on the “honor system” that you are a legal citizen when you fill out your registration form. And, let’s face it, why would someone who breaks our immigration laws by entering, staying, and working in our country illegally ever break our election laws, too? That’s a solid policy there.
Next, they’d modify existing election laws so that voters could mail-in ballots on a whim and not for a specific “absentee voting” reason. This way, in-person voting (the most secure kind of voting) would diminish, and mail-in voting (the least secure) would increase.
Next, they’d send a ballot to every voter on the voter rolls regardless of whether they asked for an absentee ballot or not. This way, millions of live ballots are floating in the system and are outside the tight custodian controls of the election apparatus in your state.
Now that they’ve hypothetically flooded the zone with millions of ballots that have been sent out to everyone, regardless of their eligibility to vote, they would need the policy to count every vote that came in, even votes that shouldn’t be counted.