Hi @AmazingTrans,
As you can read on the PHPExcel official documentation (https://github.com/PHPOffice/PHPExcel/blob/develop/Documentation/markdown/Overview/01-Getting-Started.md), you can install it copying the contents of the Classes folder into the web server.
You can copy those files into a new application defined on the stack and apply the Apache configuration files. Please, take a look at this guide in order to achieve that:
https://wiki.bitnami.com/Applications/BitNami_Custom_PHP_application#How_to_create_the_basic_application_structure.3f
Best regards,
Fernando
