================================== I don't think your idea is viable. Steering columns and wheels are usually splined so the nut doesn't do very much.
Strictly speaking replacing a steering column is a simple job but it's all the extraneous bits and pieces that take time and skin. It would be worth checking at your local scrapyard to see if they've got one on the shelf. If they have then it will show you what you need to do to replace.
Cic.