2000 Lincoln LS squeaking from the left front tired

Hey there, im hoping someone might be able to help me with a really annoying issue. I have a 2000 lincoln ls and it recently started making this awful squeaking noise when i hit bumps in the road, turn the stearing wheel, or even if i get out of the car and bounce the left front part of the car like i was doing a shock test. I was thinking the maybe the bushings on the left side were worn, or i had someone say the maybe it could be a ball joint. before the car was driven normal, it had sat in my grandpas garage for about5 years. which im guessing attributed to the problem. but like i said it squeaks(almost grinds) when i turn and go over bumps and its only on the left side...if its bushings could you tell me how hard they are to change? thanks a lot....dj