This modification will blink the brake lights as blinkers but maintain the normal use of the brake lights.
Here is a video of the mod in action:
2nd Generation Toyota Corolla ALTIS Blinker/Brake light mod.
Level of DIY: Moderate
Items Needed:

Purchase 1 x Taillight Converter: $25.00
Purchase 1 x Box of Tap Connectors: $5.00
Purchase 2 x Resistors
(so your blinkers wont blink fast): $8.00 each
Purchase whole package of ALL of the above for only $35 HERE w/ Free Shipping!!!Purchase LED MOD package $35 w/FREE SHIPPING TO USA:
Purchase LED MOD package to anywhere in the world $35.00 + 35.00 Shipping: 
Follow these directions:

Download *.pdf version instruction page here (Right Click Save-As):
LEDBLINKMOD.pdfDisclaimer: Do at your own risk! I take no responsibility in any actions you do. Educational purposes only.