Rusty bonnet latch

Hi,

I recently had problems getting the bonnet to lock. The lock/latch is completely rusted and got stuck in the open position. I managed to get it unstuck using a screwdriver and some WD40. But I'm not very happy about it. So I'd like to replace it before it completely dies.

But how? First of all, it doesn't seem made to come off. It doesn't fit through the hole in the top and at the bottom it's sealed by a protective cover (why?). Removing the cover with some violence seems an option. Getting it back on there is another story. Do I really need the bottom cover? Doesn't seem to have a purpose to me.
And where can I find spare latches? I'm sure I can get one from the local dealer, but he's a giant rip-off. So I'd rather buy one online. So if anyone knows a shop that has them (and preferably send them internationally) I'd like to know...

Getting the cover off is a real pain and I had to butcher mine but I failed to get the mechanism out at all.

If you do it post up the method.

Best of luck

take out top rad mounts and it gives you access, once cover out the way unit unbolts and removes, suggest you fit a new release cable while you are about it, as they rust seize and break, it might even be your cable at fault rather than lock...