Azure VM guest OS metrics to the Monitor metric

I hope this is the right place to ask this question. I am relatively new to Azure, and still trying to find my feet.

We have few virtual machines that are on azure that we would like to capture some additional metrics on and perhaps set up some alerts either via metric monitor alert service in portal or via the metric API. I have managed to establish and read information from the metric API which gives me the metrics from Host. In order to get more information on those VMs (memory usage, details CPU usage etc) I have set up Azure Diagnostics agent and it's sending the data to Azure Table in one of our storage accounts.

What I would like to achieve is to, send this data to monitor metric service. That will give us the option to set alerts without using application insight or log analytics services. So far I have not found any ways to set this up via Azure Portal. The only available sink is for Application insight service. I have gone through the documentations and guide, and found that, you can set up sink to monitor metric service but the example posted on the site is a ARM template which will deploy a new VM with the sink configured. I am not sure how to use ARM template to make changes to the existing VMs and set this up.

Anyone can give me some direction as to how I can set this sink to send the data to monitor metric service please? Would be much appreciated on any help that I can get.

I have found this - VM guest to metrics store (just for ref)

Thanks