How to activate 3G in my Sony Ericsson?

Hi, The 3G activation varies for different service providers. Your service provider will have a set of instruction to tell youhow to setup 3G on your phone. You can try to call the helpline of your service provider or visit the website of your service provider, maybe you can find some information to help you setup 3G on your cell phones. Have a nice day!!!

You need the service provider to tell you how. Once you register with your service provider they will activate your 3G and send give instruction how to activate it on your phone sometimes through SMS messages. You cannot simply activate 3G all by yourself only the service provider can.

We need to know a model number, in order to see if that model supports 3G. I think what you're trying to do might not be possible though as the phones only have a certain hardware set inside them and cannot be upgraded.