Convert existing stand alone UTM to HA on AWS

Hello,

We currently have an UTM deployed in AWS VPC which we would like to convert to HA (cold standby). We are not keen to using either the cloud formation template or the conversion tool for the following reasons:

- conversion tool makes the current UTM obsolete which we don't prefer.

- cloud formation deploys everything automatically which we are not, entirely, comfortable with. We always prefer to get into the weeds of the configuration. 

Therefore, I would really appreciate if I can be directed to a resource or guide on how to do it. I can't find it anywhere.

Thanks!