Opencart Version : 2.3.x
Extract the opencart-blank-theme from folder UPLOAD in root of your installation of Opencart.
Log in your admin panel.
Install blankcart.ocmod.xml via Extensions / Installer.
Go to Extension->extensions in dropdown list select Themes.
Click Instal against Blank Theme, after click edit.
In Theme Directory select blankcart and in Status select Enabled.
Go into Settings and select the store you want to apply the theme to.
In the "Store" tab, change the theme to "opencart-blank-theme".
If you decide to change the name of your theme folder, make sure to update the paths :
- line 68, path to the main.css in template/common/header.tpl