Hello,
I was looking to do the same thing and I came across your post by way of a Google search.
In case you still are trying to figure out how to do this, or anyone else comes across this, you can add markup to the wp-admin document head (ie. the <head> tag) by using the “admin_head” hook, like so:
// remove the tags section from the right sidebar
function themeslug_remove_tags_sidebar() {
echo '<style type="text/css">
#tagsdiv-post_tag {
display: none;
}
</style>';
}
add_action('admin_head', 'themeslug_remove_tags_sidebar');
