does anybody know how to replace this?

my car is a 1995 bmw 740il and it had a problem the car won't turn on when i went to bmw to ask them they told me i need to replace the ignition cylinder i bought a new ignition cylender but i don't know how to replace i know two people who fix cars and they still couldn't figure it so can anybody tell me what i can do or give me a hint or something to tell these guys so maybe they can fix it.


ps. i have another bmw that needs a brake light but i don't know how to replace it so i would appreciate it if you tell me how to do that also


thanks