Using =~ with a list

[Lysander]

I need to replace all the occurances of one thing with another.  This is simple 
enough, except that I am working with a list variable, rather than a scalar.

@body =~ s/foo/bar/;

give an error and

  for my $body (@body)  
  {
    $body =~ s/foo/bar/;
  }

appears to leave @body empty.

How does one go about this?

Thanks
Sheridan Saint-Michel