Quick/Easy way:

-Right click on the HOME icon on the left and Add a Panel
-Then right click on one of the blank buttons that's on the new panel in the main window, select properties then click Set IR
-In the window that comes up click on the View IR button near the button and a blank IR Code: entry space should appear, just paste the hex code into there and hit ok. You'll also want to rename the button to whatever the command is so you know which one is what when you open the file from the Universal Browser in the mx software.