I have pre purchased reforged how can i play w3 classic?

[Liutasil-2464]

Look at the explanation right here:

1.30.2 Patch Notes

Hail Warchiefs, Lichs, Commanders, and Keepers, We’re excited to release our first patch since announcement of Reforged! There are many great improvements, balance updates, and you can officially install classic Warcraft III if you own Reforged. The known issues will be patched very soon™. Installers can be found here: GAME INSTALLATION https://us.battle.net/account/download/ Ensure you are logged in, and browse to Classic Games Download and run the Reign of Chaos or The Frozen Throne insta…

download the game and install it. thats it!