AWS resize instance

 To resize an Amazon EBS–backed instance

1. (Optional) If the new instance type requires drivers that are not installed on the existing instance, you must connect to your instance and install the drivers first. For more information, see Compatibility for resizing instances.

2. Open the Amazon EC2 console.

3. In the navigation pane, choose Instances.

4. Select the instance and choose Actions, Instance state, Stop instance.

5. In the confirmation dialog box, choose Stop. It can take a few minutes for the instance to stop.

6. With the instance still selected, choose Actions, Instance settings, Change instance type. This action is grayed out if the instance state is not stopped.

7. In the Change instance type dialog box, do the following:

   1. From Instance type, select the instance type that you want. If the instance type that you want does not appear in the list, then it is not compatible with the configuration of your instance (for example, because of virtualization type). For more information, see Compatibility for resizing instances.

   2. (Optional) If the instance type that you selected supports EBS–optimization, select EBS-optimized to enable EBS–optimization or deselect EBS-optimized to disable EBS–optimization. If the instance type that you selected is EBS–optimized by default, EBS-optimized is selected and you can't deselect it.

   3. Choose Apply to accept the new settings.

8. To restart the stopped instance, select the instance and choose Instance state, Start instance. It can take a few minutes for the instance to enter the running state.

9. (Troubleshooting) If your instance won't boot, it is possible that one of the requirements for the new instance type was not met. For more information, see Why is my Linux instance not booting after I changed its type?

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/resize-ebs-backed-instance.html