This is a video of how I remove and replace solid steel rivets with mushroom heads in older type chassis. I normally do this when I replace a front or rear crossmember, this chassis is not going to be used, it is only to show how I do this kind of work so I just roughly sprayed it with a black spray can to give an idea of how they look when painted. I do not recommend trying this, the tools have be to hand made and the rivets are very difficult to find these days.