How to edit YML files in Prometheus Docker container?

[Apollo]

I have installed Docker Rancher on Freenas 11.2 Release and I am trying to setup a few containers.
I have installed Prometheus and Grafana in order to collect and render metrics about my system.
I am currently stuck trying to figure out the way to edit the YML files to configure Prometheus.
The GUI in Prometheus doesn't seem to allow for YML file editing and I can't seem to find the way to access such files over SSH.

Any idea?

 

[dlavigne]

Were you able to figure this out?

 

[Apollo]

No idea yet.
I have performed a search when being logged-in over SSH in Rancher.
The only indication of the prometheus.yml are in git as diff and Merged files. So not the ones.
The file doesn't seem to be accessible through this steps.
I think I need to login either via the Web GUI, or SSH to the Web address with port 9090, but I can't seem to do that over SSH due to user accoutn and password which I don't have.
According to Docker's documentation, once a container has been configured, it is not modifiable. I don't know if this includes the yml config file, though. If it were, then that would not be practical.
I was able to export Docker and Container config YML files and I can create a new container based on the above files, but I am not quite sure how reliable it is as Grafana doesn't work for this one.