Without a lot of information that you have failed to give us, here are some very sketchy instructions:
1. In the print module, click on Page Setup. In your printer driver screen choose Borderless, choose your paper type and size.
2. In Lightroom, adjust your cell size it appropriately.
3. Set your color management options appropriately.
4. Make sure paper is in your printer.
5. Print the image.
If you want more specific help, tell us what OS you are using, what printer, what problems you are experiencing, and anything else that you might feel would give us a clue as to what you have tried to do.