Chicago directions from union station?

I'm starting work at Nordstrom on Grand Ave on Friday and I'm very unfamiliar with the area. I need to get to the employee entrance on Rush between Grand and Illinois from Union Station. I have tried mapquesting it but I'm having a little trouble finding the address to the Rush employee location. I know it's next to the parking garage but I've never been there and I want to be prepared on how to get there. I'd like to walk but I could cab it. If someone could help me out and let me know how far it is from the Adams side of Union, I'd appreciate it. Thanks!