THOR, at the top of your resizing die is a nut. Put a wrench on the die body, and a wrench on the top nut. Loosen it. Now, remove the "pin" the .308 button and just stick your .311 button up inside until it barely sticks above the nut. Retighten. The Lee die set says how to do it. There is no real specific torque, just get it tight.
As a side note... if you do somehow manage to get a case stuck up in the die, loosen that nut and remove it. You'll then use a mallet to whack the button to force the case out. A plastic / rubber hammer would be best to use for this so you don't mushroom the top of the button.