In order to Install WordPress on DirectAdmin manually you need to follow these steps..
1- Create Database for WordPress
First of all you need to create database for the wordpress from your DirectAdmin Panel. Account Manager > MySQL Management
2- Download WordPress
Now you need to download latest version of WordPress zip file from WordPress website
3- Extract the WordPress.zip file to the folder or main directory where you want your wordpress to be installed for example you want it to be installed in example.com/blog folder using File Manager
4- Now you need to visit the example.com/blog
Now you need to put your database credentials in wordpress installation form
5- You will be greeted enthusiastically by the following message from WordPress. Click ‘Run the installation’ to start the WordPress five-minute installation process.
6- WordPress then asks you for the information below. Complete the fields, write down your username and password should you lose them, and click ‘Install WordPress’.
7- After installation you can login to your wordpress admin at example.com/blog/wp-admin
8- That’s it you have successfully Installed wordpress on your server with DirectAdmin Manually