How to restore beams to default setting?

I have a vocal score with quite a lot of flags.
I want to convert that into a pianoscore, which is no problem.

BUT:

I have to get rid of almost all flags and change the score back to its default beam-setting.

Using the side-palet, 1 note at a time, takes ages.
Is there a fast way to get the flags back to the default beams?

Thanks for helping me out.