2 screws hold in place to sheetmetal above radiator. Remove those, then back it out and disconnect at the accordion tubing in the middle of ducting. Or you can go all the way back to the aribox if needed.

That's the easy part, getting it back can be a bit tricky the first time. Don't try and fit it completely to gether before positioning and attempting to re-attach the 2 screws...it won't line up. Secure with the 2 screws first, and then connect at the accordion section. Hope this helps.

BTW, I'm not too optimistic about your deflap attempt based on this. You might want to hold of for some help or at least using a service manual as a guide.