*** It cannot be installed on Webuzo. CSS dosnt work. (Do not prefer Webuzo for Manual Installation). It works from 3.9.3
1) Install Composer and create zip for package and delete extra content of var folder from package (v5.8.0 check for the vendor folder in next version)
2) Install with Sample data

3) Install in www folder i.e rename your www folder and create new blank www and install in that www because Fork is installed only in root dir

4) Add these files from manual www to zip
check and move /bundles and its sub files and folders to zip

frontend/files/Users/avatars/32x32/god.jpg to frontend/files/Users/avatars/32x32
frontend/files/Users/avatars/64x64/god.jpg to frontend/files/Users/avatars/64x64
frontend/files/Users/avatars/128x128/god.jpg to frontend/files/Users/avatars/128x128
frontend/files/Users/avatars/source/god.jpg to frontend/files/Users/avatars/source

5) The version in the __requirements() in Upgrade.php should be increased when there is a Major Upgrade because it is not possible to upgrade to a Major version. This is now handled by info.xml <min_require> tag so we do not need to make changes in upgrade.php

6) check and update version in upgrade.php if it upgrade requires to delete appProdProjectContainer.php (Not required since version 4.0.0)

7) <requirement check="php" type="extension" name="pcre" version="8" operator="ge"><![CDATA[ PCRE Library Version => (.*?)\s ]]></requirement> Add this entry in info.xml once softaculous bug is fixed and launched. Also update <softversion>
8) PHP REQUIREMENT LINK : https://github.com/forkcms/forkcms/blob/master/docs/01.%20installation/03.%20minimum_requirements.md and also check composer.json
9) ckfinder_license_key in modules_settings table is hardcoded in src\Backend\Core\Installer\CoreInstaller.php files no need to configure
10)Check and change scopy code if required for i.e @scopy($__settings['softpath'].'/src/Backend/Core/Installer/Data/images/1.jpg', $__settings['softpath'].'/src/Frontend/Files/Pages/images/source/'.$__settings['timestamp'].'.jpg');.as the image created with timestamp name might be either of 
/src/Backend/Core/Installer/Data/images/1.jpg or src/Backend/Core/Installer/Data/images/2.jpg, or src/Backend/Core/Installer/Data/images/3.jpg.