..I've got the grill off but I don't see what the next step is..... unfortunately I don't have any copper pipe to try that approach so what am I looking for to release the bonnet? I can see the bonnet pin and there's a hole in the slam panel to the right of it which has something that moves in it but I don't see what is probably very obvious.....how does it actually release?
Ive also done a few now, assume we are talking Facelift here, the first time was fiddly, and was done by pushing the spring latch on the very top of the slam panel away from its location using a screw driver and a piece of steel and then working the spring and the bonnet until it released.
The second time using the above method managed to get the spring undone but it somehow slipped out of sight and the whole thing just got jammed up without releasing the bonnet pin, thats when I come up with the Copper Tube tool idea, which I assume you have seen.
http://www.omegaowners.com/forum/index.php?topic=104814.0Its is also possible, Im told, to actually undo the bonnet pin with a spanner at 90 degrees to the slotted dome part, but even if you can get something up there, theres not enough room to get proper leverage on it, and more to the point theres an upper locking nut against the bonnet panel, which if rusted in place is almost impossible to free using this method.
Since then, Ive used the Tool to do this and to be honest, once you get the Grill off, only takes a few minuets once you get the hang of it.
As TB says, where abouts are you.