Download .zip file, login with administrator privilege.
Go to plugin section, add new and upload .zip file or you can upload plugin directory via ftp.
After active the plugin, the left sidebar menu will be appeared with the name: Ultimate Media On The Cloud.
You must configure your Cloud Storage Account such as Amazon S3 or Google Cloud Storage, just go to settings and fill the credentials.
Available guide for you can take a look over how to obtain Cloud Credentials Api Key, Secret,...