Changi Airport MRT to Budget Terminal

Take the Shuttle Bus Service available at Terminal 2, not far from the SMRT station.

(Terminal 1, 2 and 3 are inter-connected by Sky Train).

airport MRT station has an exit on either end, one end leads to Terminal 3, the other to Terminal 2.
everything's indicated by signs.
anyway you'll know that you've exited into Terminal 2 when you see escalators to your right (if they're on your left, you've exited into Terminal 3).
at the top of the escalators, you should see a sign saying 'shuttle bus to Budget Terminal' or words to that effect...it directs you to an elevator on your right (near an ATM & toilets) that will take you down to the basement level, where the shuttle bus that #1 mentioned departs from.

(there's also an elevator at the bottom of the aforementioned escalators, but don't know if it serves the basement floors).

first take the free airport shuttle to either Terminal 1 or 2.

from T2 or T3, you can either take bus, mrt or taxi to town :)

IThanks I just did it. So easy. One thing you gota hand it to Singapore for is clear signs and directions.

Best airport in the world.. if you ask me.

Shouldn't take more that 15 mins - if that. Once you are on the way that is.