How can I create my own boardgame?

I want to create my own risk game with my own map and miniatures. I see on tv sometimes that people actually do that, sort of like having a publisher print one copy of a book for yourself. Are there companies that do this for people, because like I said I want to make my own version of Risk with my own map and miniatures, or would it be better to try and pitch them the idea to make it themselves and sell it nationally? I am not sure how to approach this.
Update: I just realized I forgot to tell you what it would be like. I want to make my own version of Risk that would be based on Avatar (the movie by James Cameron) because I haven’t seen anywhere that this exists and figured I would have a company make my own because I love the movie and the game so much

I would grab one of the RISK from here. use VASSAL to 'Edit" the module. Replace the Map with one you drew using some paint program. Look at how the original did the units. using the same paint program or Vassal’s internal (NATO symbols) unit drawings. Look at the other functions of the game, delete what you don’t need/want. rewrite (or use whole) what you like.
After you have all your artwork (this is usually the biggest time sink) done. For something as simple as RISK I wouldn’t think it wouldn’t take more than 10-12 hours for the rest. Maybe less depending how fancy/automated you want it.

After talking on Facebook (Sci-Fi Wargames) about Outreach (a SPI (Simulations Publications, Inc.) 1976) game. just using the files on Boardgame geek I did the map/units/charts/ and random draw for exploration in about 6 hours.

Do your parents know of this plan?