5. Prepare and publicize the contract upgrade announcement. The announcement content includes Reason for upgrade / Upgraded code link / Audit report link / New and old contract address / Trigger time / Effective time
6. Multiple sign wallets send transactions, trigger the addition of new contracts, and remove the old contracts.
7. After the delayed effective period(4 days) expires, any wallet sends a transaction, triggers the new contract to take effect, and removes the old contract. Update completed.