1.) Go into your messages folder
2.) Hit the Menu key and select "Compose Other"
3.) Select "Compose Text Message"
4.) Select the person you wish to message
5.) At the bottom of your phone's screen there are several icons, select the paperclip, this allows you to attach things to the message, making it a MMS
You can simply go to the text message window and click on the paperclip, that allows you to attach. In the media browser, you can select an image and go to the menu and select "send" and select the option to send as a text message. They just seemed to drop the term MMS, it is still the same.