This is probably a bit late now - and maybe not even that useful, so apologies - but I've found that a small pair of wire cutters (I think that's what they're for - I'm absolutely awful with tools and that sort of thing) is good for cutting the rails (and the ties between the sleepers underneath).
A few years ago I got
this kit from Amazon (well it's not quite the same one, but it'll work for this demonstration) - it's got the wire cutter bits (actually they might be designed for cutting lengths of solder but they're good for cutting the thin wires used in a lot of model railway applications). Here's what they look like (photo from that linked listing):
View attachment 115474
I hope that's somewhat useful!
-Peter