The 2020 election will not be overturned. That water ha passed under the bridge.
What is important here, is mapping the methodology, the people involved, and proof that fraud took place, for the purpose of ensuring that it does NOT happen again, especially on the scale it did in 2020.
This means some changes to eliminate practices which facilitate fraud.
Clean voter rolls of dead folks.
Ensure those who vote are residents of the state they are voting in, and that they live at an actual physical address (in other words, are real people).
Ensure that those who vote are the ones who filled out their ballots.
Cross reference addresses and check out the physical addresses where large numbers of registrations claim to be present.
Make sure that voters don't vote more than once.
Have one date by which all ballots must be cast, and end 'counting until a candidate wins' tactics.
Limit absentee ballots to those who need them, no mail in ballots mailed out. (And every ballot mailed in should have evidence of being folded to be put in the envelope.)
Each ballot should be assigned a specific and unique code to prevent duplication or double counting. This could be done after the ballot has been filled out, ensuring the secrecy of the ballot is maintained.