ive done it , with out boiling the seat,
i put the seat on some old carpet (seat down), with an old seat post fitted and the seat guts adjusted to the back of the rails i stood on the seat front and pulled back(with force) on the post and out popped the rails from the front with a little help from wd40,then just back part of the rail in a vice and gentley twisted the seat till the rails were completely out (also with wd40 to help thing along) did this on a shotgun and viscount seat in about 15mins.
hope this helps poeple as i was struggling for ages.