How do I delete first word of each line in Vim?
How about a pattern on each line?
:normal to the rescue:
:%norm dw
It basically replays the arguments as if you were typing them in normal ('non-edit') mode.
From :help :
:norm[al][!] {commands}
Execute Normal mode commands {commands}.
This makes it possible to execute Normal mode commands typed on the command-line. {commands} is executed like it is typed.