Make sure to read the *.xml files that is in the project as it tells how to properly execute from eclipse
Two good sources on explaining how to execute TestNG tests in parallel (class, test, method)
- http://howtodoinjava.com/testng/testng-executing-parallel-tests/
- http://stackoverflow.com/questions/24216163/configure-parallel-execution-of-tests-and-classes-in-testng-xml
Reference on how to pass arguments from the xml file