To reset the lights you need to open the fridge door and turn the freezer dial which will be the knob on the right and turn it to off and wait a few seconds till the lights go out.
Then turn the dial back on again and that will reset the lights and stop them flashing.
But if the temperature isn't good that will be why the lights are flashing.
What you need to do is empty the freezer and remove the back panel.
From there you need to melt all the ice in there on the evaporator and make sure its fully clear and that will get the temperature back up again.
Try that and see how it goes. If you need anymore info just get back to me.