A registered name - and expired name in grace period - can be extended at any time by any wallet address.
Additional Reading
Renewal Fees - Everything about name renewals
Name lifecycle - The lifecycle of an ENS name
Registration, renewal and gas fees are paid in ETH on Ethereum mainnet.
How to Extend Multiple Names
1. Search by address
Go to the ENS Manager App and connect with your wallet. From there, either use the search bar to search an address, or navigate to your My Names page which is the address of your connected wallet.
The returned names include those where the wallet address holds either the Owner or Manager role.
2. Select names to extend
Click the tick icon, then select any names you want to extend. Once selected, click "Extend".
3. Review warning (if applicable)
If you do not own ALL the names selected you will see a warning. Click 'I Understand' to proceed.
"You do not own all these names
Extending these names will extend the current owner's registration length. This will not give you ownership if you are not already the owner."
4. Review selected names
5. Choose extension duration
Pick the number of years you would like to extend each selected name’s registration. Review the estimates, then click 'Next'.
6. Open wallet and confirm onchain
Review the details of extend registration, then click 'Open Wallet' and confirm onchain.
Once the transaction is completed. Refresh the page and view the new expiry date.
How does the transaction look on Etherscan?
'Renew All'