Add to Chrome.
Click Add extension on the pop up that is displayed. A new tab will open in your browser once the extension is downloaded.
Click Get started to continue.

Read the disclaimer: tick the checkbox to accept and click Proceed.
If this is your first time setting up a wallet for Polkadot or Kusama, click Create a new account.
If you have previously used Polkadot.js or any other wallet, click Import from seed phrase .

If you selected, Create a new account, add a name for your account (this can be changed later) and click Onward.
Enter a password for your new account and click Let's do this.
Congrats! You now have setup an account!
Now you can move on to Connecting your account.