Change windows in apartment

Hello, hope it is ok to write in English - sorry if this is an inconvenience. I have just bought an apartment in Frederickberg C and would like to change the windows. There are 6 in total - 4 smaller (80x108 cm) and 2 larger/door (80x205 cm). The apartment is on the 2 floor (and top floor). You will see attached pictures of the building from the front and back, and of each windows. The website did not let me upload 2 last photos, but hope it is ok to understand. 1. Would it be possible to have a price estimation - for the the metal aluminum windows, in the same colour as now. 2. Can there also be a price estimate if some of my neighbours would also like to change their windows (same style). Is there a package price we can share? 3. How long will it take? 2 days or 1 week? 4. When will it be possible for you to change? Is there time in end of August? 5. Do you know if I have to check with the Kommune about laws? My building has said it is ok, but not sure if there is one more place to check. Looking forward to hearing a price estimation from you.