Buddy, you are doomed, this is something you have or you don't; you can't "learn it" in time for a test, it's about the way the brain processes stuff.
My guess is nobody has got through recruiting that can't do well on the spacial reasoning tests.
It's supposed to be about turning the 2D picture (or no picture in procedural land) into a 3D image in your head so you can control it. Although it seems more likely that the picture is more about the numbers nowadays, which means I've seen plenty of people have no picutre but a good numerical/task completion process.