So, you know Now I Know My ABCs is going to be out for it to trigger, so you don't need permanents with names that contain A, B, C, I, K, M, N, O, S, W, or Y. That leaves 15 letters. On turns 1 and 2, play a Guildgate and a Refuge. You don't need to worry about casting anything despite the one-drops in this deck, just concentrate on getting one of each of those lands out the next two turns (preferably ones that tap for white mana so you can cast the Exarch and make things easier). Among the Guildgates and Refuges, you are guaranteed to get D, E, F, G, J, L, R, T, U, and Z. That leaves 5 more letters; H, P, Q, V, and X. On turn 3, play a Snow-Covered Plains to eliminate the P and V and cast Now I Know My ABCs or the Exarch and stall a turn (It contains the remaining H, Q, and X). Once these are out and the upkeep following ABCs' arrival occurs, you win the game.
The other cards are simply to help get rarer letters out there as a safety net, or more helpfully, aid Disrupting Shoal in countering anything opponents use against your strategy. The Pacts are it's counterpart (no pun intended... well, maybe a little) and don't have a drawback as long as the next upkeep is the one you'd win.