Custom Post Type with for Custom User Roles with restricted admin dashboard

I want to achieve the following functionality without use of a plugin:

1. Create a new user role called "News Manager"


2. Create a new custom post type called "News"


3. Assign the capability of posting News to "News Manager"

However, since there are lots of other custom post types in my theme, I want that the person who is a News Manager should not be able to have access to any other types of content from the admin dashboard except uploading unfiltered html and media. I implemented this code with find-replace 'projects' with 'news' but somehow unable to achieve this functionality. Please help.