Default Buying and unlocking infuse 4g on an Indian carrier
So as the title implies, im planning on purchasing the At &t carrier locked infuse 4g from the american EBAY site and wish to use it on an indian carrier.
Before i make the purchase, could somebody tell me about the risks involved and the success rate of the procedure mentioned in this forum?
Dont want the thing bricking on me or anything.....=x

And is it necessary to have a sim card pre-installed on the phone..also what are the chances of success?
As in is there a possibility that i wont get the right code in the first 10 attempts?
Has it ever failed for anybody?