Loud engine knocking
 

I have a 2001 4.2L that has roughly 188000 miles on it. Now, I have always heard a faint knock in my motor but nothing major. Yesterday it started knocking loudly 70 miles from me being home. I had no choice but to limp the truck home. With how loud it was knocking I am socked to have driven it that for considering the circumstances. Seems to knock gets louder and faster in higher RMPs. is there a way I can take off the oil pan without taking the motor out? Also If the damage is done (which it probably is) can I reach the crank shaft with out pulling the motor?

Im open to any advice.
Thanks