Clio mk2 ph2 headlight restoration

Seeing that my headlights look a bit rough I was going to restore them with wet & dry. 1000-2500, what else would I need other than this & masking tape, clean micro fibres etc? What compound would I use after the sanding is done with? Another problem as well I have is the horn has decided not to work, it was replaced at its last mot & was wondering what I should look for to solve the problem? Thanks in advance :d



Headlights as they stand-