af9035 on amlogic s905

Hi guys, I decided to revive my old mxq pro by installing libreELEC to use usb dvb (af9035) via tvheadend. The box currently does not detect the key, so to try to solve I downloaded the fw and I tried to copy them in the /lib folder but I can not because it is read only and from ssh the chmod command does not give results. You could tell me how to solve this