Remove the metal blinds from the window (usually just a clip in each corner will do it). Move to the bathroom and hold them up (I hang mine between the shower curtain rod and the top of the surround. Flip the blinds closed, spray the whole surface with Windex, flip the blinds the other way and spray the whole surface…

Belichick: Listen, I'm in this fantasy weather league and I need to know: is it going to rain tomorrow?
Meteorologist: Rain is listed as... probable.
Belichick: YOU BASTARD