Since I received many emails on this, I might as well blog it.
All registration, rescheduling and payment are done online via http://www.mba.com/. Register yourself if you have not done so. Make sure your information is correct as whatever info you provided will be reflected in your GMAT official score report (yes, you can still change the info even on that test day).
Bookmark this page - http://www.mba.com/mba/TaketheGMAT. All you need to know about GMAT is found here.
There are only 2 test centres in Malaysia:
a. Central Region
Word Ware Distributors SDN BHD (next to Eastin Hotel)
Level 3, Unit 10, Block F Phileo Damansara
1Jalan 16/11, Off Jalan Damansara
Petaling Jaya, Selangor, 46350Malaysia
Tel: 603-76652911 (Speak to Willy)
GPS: 3 12 67 N, 101 64 34 E
b. Northern Region
Alpine Reliance (M) Sdn Bhd
1-3-16 Krystal Point Corporate Park,
Jln Tun Dr Awang
Bayan Lepas, 11900Malaysia
GMAT schedule: https://www.mba.com/NR/exeres/B2D66353-453B-4486-A745-C2451DB8D861,frameless.htm?action=appointmentSearch&SSLSwitch=1
Those from other states/regions, you will have to fly in/drive/take bus/taxi or cycle to either centre.
The fee per test is US$250. Every rescheduling costs US$50, if done 7 days before the test date; else, another US$250.
Good thing about Malaysian test centres, there are not many takers in a day. On average, there are only 200 test takers in Malaysia in any year compared to 2000+ and only 1 centre in Singapore. You could have the whole room to yourself.