The hard way, is how! If you're lucky, it might be jammed where you can reach it by hand. More likely, it will be jammed just beyond where you can reach. It's no good trying to drive it further down the pipework, you'll just move the obstruction to somewhere more expensive to fix. There's a chance it's jammed inside the WC pan adaptor, the section between the ceramic toilet pan and the black/grey/orange waste pipework, in which case you remove the WC to gain useful access. If you are lucky, you will find it. If not, then you may well have significant problems later on. If the water is slow to leave the bowl, you know you've got trouble, the type which will only get worse - e.g. the bowl overflowing sewage all over the floor when the WC is flushed.
You should do whatever is needed to find and remove it, sooner or later it will likely wedge sideways somewhere completely inaccessible and then you'll have fun. If it was very short, it might pass through completely. Keep an eye on the discharge rate from the WC pan as a sure indicator of pipework conditions.
Sparks (the Plumber)
May 2018