You'll need to cut your old colum and shaft shorter, do a little machine work on the end of the shaft. In the end of the column tube you install a bearing possibly with an adapter bushing.
Also make a mount to attach the column to the floor.
For the telescoping shaft and joints there are a lot of choices, I'd go with something like these
http://www.flamingriver.com/index.php/products/c0008I used joints and a shaft from these folks
http://www.borgeson.com/xcart/ and while they work just fine I think Flaming river will have a better quality product, and will try them next time.
Don't have a great picture of my setup, but I did use the original column.
http://rides.webshots.com/photo/2055030960080251109iezFAOGrigg
