I am in the process of replacing my power steering pump and the low pressure line. While I am at it, am going to flush the system and replace the fluid. I went to "loosen" the high pressure hose (on the top-similar to a large brake line) and realized really quickly that I need some advice on loosening said bolt.

I have a used pump that seems to be in better shape than mine but the hoses (save the low pressure "clamp on hose" seem to be fine, at least the do not leak. I am trying to just remove and replace the pump and one hose, but I need help getting the "high pressure side" bolt loosened. Before I forget, it is a 1990 Volvo 240 station wagon with 328,000 miles. The pump is the original pump. Please help.

Thank you in advance.