Cosmos is using a delegated Proof of Stake Consensus Model, which allows $Atom holders who do not want to run a validator node by himself/herself, to earn rewards by delegating to a validator.
Staking $Atoms simply means to delegate tokens to a specific validator, who then gets the rights to use your balance for voting for consensus on a new block. Atoms never leave your wallet and you are always in full control of the funds and private keys.
The whole process of staking your Atoms is easy, could be done in a secure way and takes a few minutes.
Now with the beta release of Lunie Web-Wallet, it became incredibly easy to redelegate too! You could also use Lunie to participating in governance and claim and delegate rewards on the Cosmos Hub.
What is great about Lunie is that it will not ask for or store your private key or seed phrase. You could find out more about Lunie here. The only prerequisite to following this guide is that you need to have Ledger Cosmos App set up since it is must have to send and sign any transaction with Lunie.
Open Lunie web-wallet, plug in the Ledger device and Sign In.
After you access your account, select “Staking” tab on the left.
It will bring you to the list of validators, your account has delegated $ATOMs to.
If your new preferred validator is in the list displayed, select it from the list. Else, if you want to re-delegate to a validator you have not staked $Atoms with before, select it from the “Validators” tab on the right.
Click the “Delegate” button on a right-hand side.
In a newly opened section, click on the drop-down list in the “From” section to see all places where you currently have $ATOMs available or staked.
Select the account you want to re-delegate tokens from.
Input the desired amount and click “Next”.
Verify the number of tokens to re-delegate and transaction fee to pay and click “Next”. You will be prompted to sign the transaction on the Ledger Device. After that click the “Submit” button and the process is complete.
!!! One thing you should probably keep in mind that $ATOMs could only be re-delegated once in a 21 days period.
@FollowTheChai also mentioned that: your reward balance will be withdrawn to your account upon redelegation. Consider it to be a side effect that takes no additional fee.
If you still have not decided who you should delegate your hard-earned $ATOMs to, consider reading the following article: How to Choose Cosmos Validator.