How do I update the theme?
To update the Theme, login to ThemeForest, head over to your downloads section and re-download the theme like you did when you bought it.
Before doing the update I recommend you to backup your current theme folder, just for the case something goes wrong.
Extract the zip’s contents, look for the extracted theme folder and under /wp sub-folder you will see the theme folder: chapter_two
Then upload that folder, using FTP, to the /wp-content/themes/ folder in your server, overwriting the old one.
After updating you should re-save your theme options in order to get your custom styles rewritten to the proper files.
If you’ve changed some core files, you should reproduce the same changes in the new updated files.