Programming APT LCD (change settings)

[sn0wye]

Hello,

Have any of you ever programmed a APT LCD display?
I've got APT 500S-X display and i would like to change settings which i cannot change using service mode after passing code 1919 (Dunno why, there is soft lock or something but settings like wheel size and max speed after passing code are non-configurable - they are visible but pressing + or - did nothing - look

https://imgur.com/a/c7XI72R

).

So im looking for a way to change it using a PC. Should i use a St-link V2 or something? This LCD has UART protocol.

Thanks for any help.