DDJ SR not connected for firmware update

I would like to install the latest firmware on my DDJ SR, because im having distortion issues every time I record a set.

I've downloaded the latest firmware but can't figure out how to install it and I've downloaded the latest JAVA software (from your website). I read somewhere that the controller needs to be in UPDATE mode, for it to be connected, but I tried holding down shift-sync on the left deck but nothing happens.

It keeps giving me the same error, your ddj sr is not connected.

Please help.