Transfer instance from one EC2 account to other

Recently we decided to migrate our instances to a newly created EC2 account. I was assigned the task of migration and initially my impression of work was that it would only involve fiddling with aws credentials and I'd be done. However I couldn't have been any wrong. Migration of instances from one EC2 account to new one was a job in itself for me. Following are the steps which I had to follow to migrate the instances:

1. Create AWS key pair for new account.
2. Create X.509 certificate for new account.

There are separate procedures which I too to migrate Linux and Windows instances.

Linux instance migration:

1. Copy X.509 certificate to some directory on instance which we want to migrate. I copied private key and certificate to /opt/ec2/keys directory.

2. Login to instance.

3. Download and extract ec2-ami-tools to /opt/ec2.

4. Set a variable EC2_HOME: export EC2_HOME=/opt/ec2

5. Set PATH: export PATH=$PATH:$EC2_HOME/bin

6. Bundle the instance:

ec2-bundle-vol -d /mnt -k /opt/ec2/keys/pk-XXX.pem -c /opt/ec2/keys/cert-XXX.pem -u XXXXXXXXX -e /opt/ec2 -s 10000

For details of using ec2-bundle-vol, use --help

7. Upload bundle: before uploading bundle I create a S3 bucket called ami_from_other_account on my newly created account.

ec2-upload-bundle -b ami_from_other_account -m /mnt/image.manifest.xml -a XXXXX -s XXXXXX

8. Register the AMI: in order to register the AMI we need ec2-api-tools and they need to be setup properly. One needs JRE and JAVA_HOME variable appropriately set. I had setup ec2-api-tools on my machine. I had also copied private key and certificate files to /opt/ec2/keys on my machine
The private key and Certificate are one's for newly created account.

ec2-register ami_from_other_account/image.manifest.xml -K /opt/ec2/keys/pk-XXX.pem -C /opt/ec2/keys/cert-XXX.pem -n AMI-Blah-Blah-Blah.

Windows instance migration:

1. Download and extract ec2-ami-tools and ec2-api-tools to /opt/ec2 directory.

2. Download private key and certificate file to /opt/ec2/keys
3. Share AMI of existing Windows instance with other user.

4. Run the instance thru new user account.

5. I created a S3 bucket called win_fac to hold my new AMI files

6. Bundle running instance

ec2-bundle-instance i-XXXX -b win_fac -o AWS_ACCESS_KEY -w AWS_SECRET_KEY

7. Register new AMI

ec2-register win_fac/image.manifest.xml -K /opt/ec2/keys/pk-XXX.pem -C /opt/ec2/keys/cert-XXX.pem -n WIN_AMI.