Using Magento 2 composer is a brillant way to install / uninstall Magento 2 modules.

I will show you how to install MageShip extension after completed purchase on Magento Marketplace.

You will need to connect via shell access to your server (SSH)

Change directory to your Magento root folder (here "magento" being where app/, bin/, css/ folders can be found)

cd /public_html/magento

next command is addressing your composer

composer require maurisource/mageship 0.1.0 --no-update

composer update

the files are downloaded, we now need to run the following commands to complete installation

php bin/magento setup:upgrade

php -d memory_limit=2G bin/magento setup:di:compile

php bin/magento cache:flush

Voilà! Done. You may now login your Magento admin and configure your module settings!