Install a printer app (I prefer Cloud Print - it seems to work no matter what you do to it). Set it up (it should find any printer that's available on your wifi network, even if the printer is plugged into a computer). Now, when you're looking at a text, long-press it and you should get a menu. One of the items is Share. You "share" text with the printer app to print the text. (Any text, in any app, including your texting app.)