First: Right click and copy the following link to your clipboard: http://www.technicpack.net/api/modpack/minewars-3
Second: Open Technic Launcher and on the left side scroll until you see "Add New Pack" and click it.
Third: Paste in the copied URL and hit "Add Modpack".
Fourth: Hit "Play" and it will download and launch the MineWars pack. This will also update the pack if any updates are out for download.