Thanks for your answer,
@
damianisko5
.
The first video is for the removal of the radio remote control, which is very easy and I already managed to do.
It seems the second is using an interface adapter module to convert the radio remote control resistors' values to the ones of the aftermarket radio, which is what I want to avoid... What I need to do is take out the circuit board of the remote control, so that I can change the resistor values to the ones that the aftermarket radio recognizes, as shown in the previous PDF file made by a member of this forum I attached.
By the way, the radio I want to instal lis the Pioneer MVH-S520BT:
https://pioneer-car.eu/mvh-s520bt/mvh-s520bt
The diagram of the car remote control is this:
FordFocus_esquema.jpg
And the one of the Pioneer radio is this one:
Pioneer_esquema.jpg
Thank you.