horst,
Go to aMule preferences->Remote Controls. There you will find "External Connections Parameters". Check "Accept external connections" and "Use TCP ports instead of unix local sockets". Then enter a password.
That password should be given by any program trying to access aMule from the EC socket (External Connections). The programs amuleweb, amulewebDLG, amulecmd and amulecmdDLG all support this. Besides, if using these programs locally, you can give them the parameter -f, so that they fetch the password from the file ~/.eMule, that way you don't have to enter the password on the command line.
Notice that webserver passwords are different from EC password and are only used by amuleweb* to validate user access from a web browser.
Cheers!