Got a German QWERTZ but for some reason its QWERTY layout with extra german letters. This is actually great as im used to QWERTY but for some reason the keyboard is mapped like QWERTZ but the physical layout is QWERTY so when I press Y it actually types Z and vice-versa.

Would it be possible to remap this and also add a umlaut for the key to the right of P? Would really appreciate if someone could please point me out into the right direction to get me started.