I am a newbie to E53's but I just upgraded tonight and it was a piece of cake.

Used Imgburn and d/l the v31 from the link. At 1x speed.
Memorex CD-R
Did verify. All sectors good.
Opened driver door.
Opened hatch.
Ejected map DVD.
Turned to position 1.
Inserted CD-R
It loaded and rebooted great.