Start connection from another apk

How C I start droid vnc from another apk in java language?

I tried
Intent launchIntent = new Intent(“net.christianbeier.droidvnc_ng.MainService”);
PackageManager pm = MainActivity.this.getPackageManager();
List resolveInfo = pm.queryIntentServices(launchIntent, 0);
if (resolveInfo == null || resolveInfo.size() != 1) {
return ;

without success

Thank you for answer.
I found it few days ago. To start one APK from another. Next problem is connect to listening client from JAVA code