I am not allowed to play with power tools so I cut the front with a sharp craft knife I had to cut some from the top and dawn the side. So now I had the main part and the roof part with the tow windows that goes at the top I can re-use as it is. So that just left the small section on the right. I got the original front and cut a some thick card the same size.  in the card where the windows where on the shop front I cut holes for two smaller windows  I had.  I painted all the windows in my favourite Farrow and Ball blue paint.  I am now waiting for them to dry and then I can paint the walls.