How to unlock Sidekick 3 T-Mobile?

I like to know how can I unlock my Sidekick 3 T-Mobile. I put a differnet sim card and it always asks me to type the secret code.

Thanks

You can unlock your sidekick by visiting unlockyoursidekick.com There you will be able to purchase a license key and download the software to instantly unlock your sidekick.

If you want to use the other country sim, you have to unlock your mobile.This unlocking can be done through codes. I found an unlocking service at Mobileunlocksolutions.com .This is the online service provider which offer the service for your mobile. With the help of this you can unlock your mobile easily.