Just write down paths to identity and data from this app, then remove the app.
Enable ssh, login via ssh and follow the mentioned setup with docker. You need to skip SETUP step, since it’s already done and run your node right away using correct paths.
Or use the method suggested by @sean, the example of docker-compose.yaml for storagenode and watchtower you may see there:
However, the port section should be adjusted to
ports:
- 28967:28967/tcp
- 28967:28967/udp
- 14002:14002