I solved my problem.
See my function below to help the community ! 
private ConverterComputerSpec BulidLiveSourceV2VSpec()
{
ConverterComputerSpec computerSpec = new ConverterComputerSpec();
ConverterComputerSpecManagedVmLocation managedVmSourceSpec = new ConverterComputerSpecManagedVmLocation();
managedVmSourceSpec.uuid = <UID OF YOUR VM SOURCE>
computerSpec.location = managedVmSourceSpec;
ConverterVimConnectionSpec vimConnectionSpec = new ConverterVimConnectionSpec();
managedVmSourceSpec.vimConnect = vimConnectionSpec;
ConverterVimConnectionSpecLoginVimCredentials vimCredentials = new ConverterVimConnectionSpecLoginVimCredentials();
vimConnectionSpec.credentials = vimCredentials;
vimCredentials.password = <HOST SOURCE PASS>
vimCredentials.username = <HOST SOURCE USERNAME>
vimConnectionSpec.hostname = <HOST SOURCE ADDRESS>
vimConnectionSpec.verifyPeer = false;
return computerSpec;
}