1990 sierra k2500 tilt column moves around. also 4wd won't engage.

1990 sierra k2500 tilt column moves around. also 4wd won't engage. I have already tightned the stearing wheel once to be told that it probably wouldnt last. Now it won’t start! I need to know how to take it out and whether or not I can put a non tilt steering column in its place and what years can I use if it is possible to change it from a tilt to a standard column.