AWS - EC2 - Change PEM Key

AWS - EC2 - Change PEM Key

1. From the AWS EC2 Console go to "Key Pairs" and generate a new key pair (eg: NewKey.pem); Download the generated pem key, and chmod it to 0666

2. Use the new pem key to generate a public key
 $ ssh-keygen -y

 When prompted, enter the path to NewKey.pem. This will generate NewKey.pub 

 Tip: Edit NewKey.pub and append the key's name so you can identify it easier in the next steps.
 Just append a single space, then a tag/name for the key 

3. Add the new public key to your instance

   $ cat NewKey.pub | ssh -i OriginalKey.pem user@amazon-instance "cat >> .ssh/authorized_keys" 

4. Test the new key by logging in and removing the old/original key
 
 $ ssh -i NewKey.pem user@amazon-instance 

 $ nano ~/.ssh/authorized_keys 

 Find the line containing the "original" key and remove it.