2003 Chevy Silverado oil lights coome on no oil presure

I think i need to replace oil pum. So when i stared to do the work I have to remove the cross brace under the oil pan. I took lose the 4 bolts holding it but the brace is on there so tight i could get it to budge not even with a crow bar. What do i do? Did I mess a step thats not in the book?
David