-Download the modpack from Dropbox.
-Unzip the .zip you just downloaded.
-Run the forge installer.
-Drag the "mods" and "Flan" folder into your .minecraft.
-Start up Minecraft, and everything should run fine.
Type in the modpack name (ModernEra) or paste the following url into the search box.
Finally, click Install at the bottom right of the launcher after you select ModernEra from the list on the left. The launcher will handle everything else!