A short description is not needed for a pack this amazing.
Install R & R Build Server Pack 1.8.9
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 (R & R Build Server Pack 1.8.9) or paste the following url into the search box.
Step 3
Finally, click Install at the bottom right of the launcher after you select R & R Build Server Pack 1.8.9 from the list on the left. The launcher will handle everything else!