How do I get money from my 401 k when I am no longer working for that company

You contact the plan administrator. But unless you are 59 1/2 you do not want to withdraw this money. You can roll it over into an IRA if you don't want to keep it in the plan.

Are you planning on rolling it over? Your HR department should have the paperwork you need.

To cash out, contact the company you have the 401k with. Be prepared for heavy tax consequences, though.