The unclued lights (and 4 Down + N) are of a kind and along with the suggestion given by the title, they indicate how all the solutions (clued and unclued) have to be adapted before being entered into the grid. Ignore two accents and one apostrophe.
 

Across

 
6    Carillon playing opening arrangement of 34 (4)
12    Reactin’ badly, for sure (7)
14    Spade I swapped for a weapon (6)
15    Facetious interjection of Turkish governor that’s worthless in Wick (7)
16    Tailless rodent, active at hollow (4)
20    Make a fool of old boy – dock a shilling (3)
22    Mild...