How to override `admin.hbs`

Overriding templates is a fairly nuclear solution, and some one-off fiddly javascript or css like

// NB I am pseudocode
$('.api-nav-item').attr('disabled', 'true')
.api-nav-item { display: none; }

would definitely serve you better here if you can get away with it.

If you need to override a whole template, theme component is the simpler way that I know of, with something like

<script type="text/x-handlebars" data-template-name="admin">
  <div>Hello world!</div>
</script>

If your plugin is going to go onto a bunch of instances, or you need to automate the installation more for whatever reason, you can go with my jack-wild solution from mingle, which automatically populates a theme component when the plugin is installed (but note that this is well within the realm of mad science :man_scientist:).