Update 
Step O1 
Extract downloaded zip file
Step O2 
Remove .env file and zip all files and folder again
Step O3 
Upload new zipped file to your server and replace existing files and folders
Step 04 
Run composer install --no-dev on your root directory
Step 05 
Run php artisan migrate to create necessary database table and fields
Step 06 
Run php artisan optimize to clear existing cache and optimize cache
Done. If you need further assistance contact us through codexshaper@gmail.com