Tiagra Gear Cable Change

[razfoil]

Hi, I'm in quite an unusual situation...
I have a Giant SCR Ltd racing bike with Tiagra Shimano gears,
I was out cycling the other day the back derailler gear cable broke.

Now for the unusual bit --> the gear cable snapped within the gear lever bit on the handlebar, and i'm having great trouble getting it out.

I understand how the new cable is to be threaded through to replace the old one, but with short section of sharp snapped gear cable and the its block bit jammed within the shifter so I can't put it in

Having looked at the specification and documentation of taigra gears on the shimano website:
(http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/road/tiagra/product.-code-ST-4500.-type-.st_road.html)
I'm still not sure how i can get the old block out of the shifter... its almost impossible to take it apart... and so I have been trying to wiggle it out with pliers, taping the end to make it small enough to push out, and tried to just push it through by using the new cable... but have had no luck

so any advice would be welcome ^^

---

http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/road/tiagra/product.-code-ST-4500.-type-.st_road.html