ELB encryption and attaching to EC2

Just starting out here! but here is my Question., I have an EC2 instance running my apps all configured and working, however now the requirement have changed, ie, we need to have a ELB encrypted, here is my problem, i can make a snapshot and encrypt, and then create a volume out of that ELB which is encrypted. BUT if I try to attach to my existing instance, i.e. detach the unencrypted and then attach the encrypted. it says this instance does NOT support encrypted ELB. So, i have this instance with all my installed libraries etc, would it be a good idea to either changed instance type and then try to attach the encrypted instance or create AMI , and then create another instance and then do the required? any suggestions will appreciate .