I just want to know if you got the dust cover off yet...
If you're serious, send us an email to info@albertatacticalrifle.com and we can order one for you.
Get a towel
Put on a flat surface thats very stable (a rubber tire layed down with towel over it is really good, so you wont damage the upper)
Slam upper with the pin and hole facing down (slam on the threads basically) let inertia knock the pin down a little
Then grab with pliers after some of it comes out.
You may want to get some very thin lube in there with the pin also
I just did this with a dead blow hammer, hitting front of reciever-worked fine.