Password Change Screen

I have been successful thus far about locking my users out of the admin panel. There are areas of my site that I have visible to only logged in members, but I don’t want them seeing the admin panel. The one issue that I have though is that I need them to be able to change their password, but nothing else as the user info is linked to a CRM system. So I was looking at making a page to just change their password, but I am lost at how I would do that. Unfortunately there is no plugin that has been made for this, and I am still new to PHP. Any ideas or suggestions?