I have a private (ie self signed cert) that I want to get onto the cert manager

How do I go about doing this, normally on a PC you can do this from within Internet Explorer by an option to install the cert

I cant find a way under the built in web browser, if I look at the details of the cert it is fine and browser says it is ok, however it doesnt appear in Cert Manager

The reason for doing this is I want to try out MfE but it doesnt work which I believe is because it isnt a public cert

Thanks