I have a Lightsail instance with Amazon Linux 2023 I wanted the Minimal AMI - how do I fix this?

Switching from the standard Amazon Linux 2023 AMI to the Minimal AMI on your Amazon Lightsail instance requires a few steps. Unfortunately, you can't directly convert an existing instance to a different AMI, but you can create a new instance with the desired Minimal AMI and migrate your data and configurations. Here's a step-by-step guide:

1. Backup Your Data:

   • Backup any important data, databases, configurations, or custom code from your current instance. You can do this by manually copying files to a storage service like Amazon S3, or by using any backup tools you prefer.

2. Launch a New Lightsail Instance with the Minimal AMI:

   • Go to the Amazon Lightsail console.
   • Click on the “Create instance” button.
   • In the instance creation process, select the “OS Only” option.
   • Choose “Amazon Linux” and look for the version labeled as "Minimal".
   • Configure your instance settings (like instance plan, instance name, etc.), and then create the instance.

3. Configure the New Instance:

   • Once the new instance is up and running, connect to it via SSH.
   • Install any necessary software that your application requires. The minimal AMI comes with fewer pre-installed packages, so you might need to install more items than you did with the standard AMI.
   • Adjust any system settings and configurations to match your requirements.

4. Migrate Data and Applications:

   • Transfer the data and applications you backed up from your old instance to the new one. This can typically be done over SSH using SCP or SFTP.
   • Ensure all services and applications are correctly configured and working as expected.

5. Update DNS Records (if necessary):

   • If your instance is accessible via a domain name, update your DNS records to point to the new instance’s IP address.
   • Remember that DNS changes might take some time to propagate.

6. Test the New Instance:

   • Thoroughly test the new instance to ensure everything is working correctly.
   • Check all functionalities of your applications and services.

7. Decommission the Old Instance:

   • Once you have confirmed that the new instance is working as expected and all data has been migrated, you can stop and eventually delete the old instance to avoid incurring extra charges.

8. Monitor the New Instance:

   • After migration, monitor the new instance for any unexpected issues.

Remember, while this process is relatively straightforward, it's crucial to have a complete backup and possibly a rollback plan in case something doesn't go as expected. Also, consider any downtime that might occur during the migration, and plan accordingly to minimize impact on your users or services.