Hi Gerald. Once you have installed the new firmware to activate the mirror lockup follow this processes.
Camera - On
Select - Menu button
Use ">" button - move menu selection to last setup option. (Show's Language, Video system, Communication, Clear all camera settings etc)
Use "V" butoon - select "Custom Functions"
Press "Set" button
Use ">" button - Scroll through to option number 12 (see top right hand cnr of the screen)
Press "Set"
Use "^" button to toggle between "enable" and "disable"
Press "Set"
Use ">" to scroll to option number 17 "Mirror lock up pause time"
Press "Set"
Use "^" to scroll through shutter release time delays (1.5 sec, 3, 4.5, 6, 7.5 and 10 sec delays)
Press "Set" to select time delay
Press "Menu" Button to exit.
From there the mirror lockup will operate every time you press the shutter release button in a Programmable mode (P, Tv, Av, M)
Good luck with it.