MFI Multiloader is a choice but this is illegal and there is a HUGE chance of you bricking your phone. I unlocked my 8900 by purchasing an unlock code over at ebay for $3 bucks since Rogers doesn't provide unlock codes.
As people above me have stated you can call and usually get it for free within a couple days but on ebay there are trusted sellers that you can buy for only 3.88 ive seen and get it within 10 minutes