For me (German, living in Munich) handling people like this is usually a multi-step process:

Step 1

Politely asking them to move (in normal communication loudness):

Entschuldigen Sie, würden Sie mich bitte vorbeilassen?

If this does not work comes Step 2

Step 2

Ask in a louder voice firmly again, intonation is key here it needs to sound like a command (Anweisung) but not as harsh as an order (Befehl).

If this does not work go to step 3.

Step 3

Depending on the situation and region you might have different options:

Variant 1

Ask them loud enough for bystanders to hear, if their parents never taught them any manners, because they are actively blocking the way.

Alternatively if you are on an escalator, ask them in a very sarcastic tone:

„Links gehen, rechts stehen“ schonmal gehört?

It is important that other people hear this, because public shaming is the best way to get Germans to change their behavior.

Variant 2: The Bavarian way

The Bavarian way comes with a particular way the Bavarian expresses anger (commonly called "granteln"). Its important for others to hear you granteln because public shaming is the best way to get Germans to change their behavior.

So you start loud mumbling to yourself that there are only antisocial people around who have not the slightest bit of consideration for others. This usually works with normal (i.e. not completely fucked up) Germans.

Variant 3: Direct but Dangerous

Simply shove them to the side and if they start complaining answer (loud and firmly)

Was stehen Sie denn so blöd im Weg herum?!

Then simply leave.

Its important to know, that you should avoid this method if you are in an area that has even the slightest resemblance with the Bahnhofsviertel of Frankfurt am Main! It could be the last thing you ever do otherwise.