It may have multiple leaks but IF it were only the lower seal it is potentially a DIY job, although not really an easy one and probably not a long term fix. You have to take off the left tie rod, center link, pitman arm, then pull out a seal and replace. Not that hard once you get to the seal but not really easy to get there. To me it would be worth cleaning it up and seeing where it is leaking from. If it's coming from higher up on the gearbox you're toast. It could be a hose which is a DIYer - again not exactly easy.