Just put it on the command line after psql
:
psql example.sql
psql
will take the file and run each line to the server.
If the server is not running on your computer, you will need to specify the hostname to the computer and a username to log into the server with:
psql -h server.postgres.com -U username example.sql --password
To send multiple files, just list them all:
psql example1.sql example2.sql example3.sql