depends on how good you are with a die grinder. I use a hacksaw and then a file. Depending on the braze on, of course. If the braze on doesn't have a lot of contact area with the tube, you can concentrate the heat on the braze on and not put much heat at all into the tube. But it looks like most of the ones on that bike are going to be hard to get off that way. And it's possible they are welded, in which case you will destroy the frame using heat to remove them.