Q: imessage

If you no longer have your old handset, visit the Apple Support site, login with your iTunes account details and deregister your device.

Read more:  Switching from iPhone to Android? Switch off iMessage | PC Pro blog http://www.pcpro.co.uk/blogs/2013/11/28/switching-from-iphone-to-android-switch- off-imessage/#ixzz2wylU8fOK

If you no longer have access to the phone, contact Apple Support.

HI

Now i had the similar problem, but i bought an ipod but previous owner didnt deactivate his imessage (still with his email address). So how can i change to my email address?

Thanks.

The previous owner not removing their Apple ID from iMessage has no effect on you whatsoever. Do you mean they didn't log out of Find My iPod and the device is now locked to their Apple ID? If so, unless you can get them to remove the device from their account, it's useless to you.

See this article:

What to do before selling or giving away your iPhone, iPad, or iPod touch - Apple Support