Retrofitting LED rear lights

[Jonjo]

Hi guys, 

I have the Sline LED lights and I am changing my halogen to these, I just want to know what coding needs to be done, I have the conversion adapters for it already.

I been told that coding can screw up the car but I need an honest opinion, as what I was told is that could bring up bulb faults on the message screen.

 

Cheers and any help will be taken gratefully.

 

Jonjo.