How to installing child theme?

1. Go to www.xtratheme.com
2. From menu click on My account
3. In My Account page find Purchase history
4. Click on View and Download button

1. Find XTRA Installable File and download file
2. Find XTRA Child Theme and download file

1. Go to your website Dashboard > Appearance > Themes
2. Click on Add New Theme

1. Click on Upload Theme button
2. Choose ZIP file
3. Click on Install Now button
4. Wait until WordPress installing theme

1. Click on Activate link
2. Wait until WordPress redirect you to Welcome Page

Repeat steps 3-4-5 for installing and activating child theme, then in child theme you can modify or add any codes and files.