You can find the permissions & licenses in the modpack's folder (readme.pdf), for Windows it's "%AppData%.technic\modpacks\gflash".
Install Gflash
Step 1
Installing a modpack using the Technic Launcher is easy. If you don't already have the launcher downloaded, visit our download page to get the latest version.
Step 2
Type in the modpack name (Gflash) or paste the following url into the search box.
Step 3
Finally, click Install at the bottom right of the launcher after you select Gflash from the list on the left. The launcher will handle everything else!