The following are symbolic links:

• fontawesome-all.min.js
• jquery.slim.min.js

These files are referenced from the HTML, and they point to specific versions. To upgrade you simply need to add a new version and updated the symbolic link.

Where necessary (e.g. in _includes/head.html) you'll also need to update the integrity attribute. Generate a new hash using this command:

openssl dgst -sha384 -binary FILE.js | openssl base64 -A