The way mentioned in the article, might be slightly easier but as I am a vim user and have the vi mode enabled in bash,my command chain for this action is:

^[ k I sudo

Esc (^[ = Esc) exits to command mode, k goes to the previous command, shift-i moves the cursor to the beginning of the line and sudo is well sudo.

Slightly more complex but it is reflex from all of the other programs I use.