Removing stuck or seized seatpost?

So looks like I am gonna have to try and cut it out but I am shitting myself, when you eventually get through the post is it obvious? how will i know I aren't also cutting my frame in half? Its 531c so the tubing is gonna have thin walls. also how many cuts do you need? will the sections just peel off the sides once I cut through?

don't bother wasting your time trying to cut it out.
just cut in fairly near the top of the seat-tube, and fill with a mix of caustic soda and water, right up to the top.
change it every day until it has burnt it all away.

oops, is it a lugged frame?
if so you'll have to remove the b/b and plug it.