If you need to update Magento 2 Rocket Javascript by Magefan, please follow the steps below.

Note: the updating instructions depend on the method the Rocket Javascript extension was installed with.

Update using composer

If the rocket javascript module was installed via the composer (check if vendor/magefan/module-rocketjavascript folder exists), then you need to run these simple CLI commands in Magento 2 directory:

composer remove magefan/module-rocketjavascript
composer require magefan/module-rocketjavascript ^x.x.x
# replace x.x.x with the version you want to use
php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy

Note: if you don't want your website to be down during deployment, try these zero downtime deployment commands for Magento 2.

Update using archive and FTP

If the rocket javascript module was installed via FTP (check if app/code/Magefan/RocketJavaScript folder exists), then follow these commands:

1. Download the latest version of rocket javascript extension archive from magefan.com.

2. Extract archive.

3. Make the backup copy of the app/code/Magefan/RocketJavaScript folder on your server and then remove it.

4. Using FTP, copy app folder from the archive to your Magento 2 Directory. 

Update Magento 2 extension via FTP

5. Run update CLI commands in Magento 2 directory:

php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy