How would one go about getting the information to a print shop to have it printed ?
If you are using a local shop, the easiest thing would be to put the image on a flash drive. If you are using an internet service, they will probably have a facility to upload the file.
You most likely will have to rescale the image, and probably crop to fit the size you want. This gets a little complicated since you will be changing the resolution of the image. If you don't understand such things, it would be best to find a shop that will do this for you. Easy for them, but they would have to understand what you are trying to accomplish. One thing to realize is that each pixel is going to be pretty big. You will often get a warning about low-resolution. It is OK because of the viewing distance, but unless the provider understands, they will fret about it.
Such issues are why you might consider one of the hobby-oriented vendors. They cost a lot more, but if you don't enjoy this kind of thing, it may be well worth it.
There was a deeper discussion on this topic a while ago:
https://ogrforum.com/t...ply=9173459980976234