Also? Be specific in what you are changing.
Don't search and replace all http: with https: that will break things. Instead be specific and change your own domains from http://your-domain to https://your-domain one at a time.
You can confirm that the HTTPS URL works before you do this. Visit http://your-domain/readme.html and confirm that the read me page loads. The do the same with https://your-domain/readme.html and if that works you are good to go.