My steering pump is vibrating when making turns when checking fluid level I find that there is a lot of foam in the steering fluid, this indicates to me that I need to replace the pump, or the fluid. Is there a way to drain the fluid to replace with clean one?, or if I need to replace the pump should the two 14mm. bolts under the pump are the ones to be removed, these appear to be holding a base between engine and pump, the pump appears to be attached to this base with three 12mm bolts and seem impossible to get to, is there a special tool that I should use?
Please advise which course I should take.

TonyO