If you are talking about brake hose, yes you can do it yourself. You will
have to bleed the brake system afterward.
The steering wheel... there are many factor involved... how much play are
you talking about? 20mm? More? If more, you may have a broken flex disc
joint... that is supposed to break in the event of accident so the steering
wheel doesn't jam up against you.
If you are talking about 5mm, it can be number of things... but first thing
to check is the entire steering assembly in the front that are hooked up to
your tires... jack up the entire front end up and have one of you wiggle the
tire to see what is loose...
idler arm bushing?
upper control arm?
tie rods ball joints?