Ok, so I've removed the 3 pins from the gas block, and the rail is unscrewed. But the gas block isn't coming off. Would the gas tube connected to anything within the receiver (it appears not to be), or could that pin that I don't know what on the bottom of the block be preventing it from moving still? The only way i can see one could remove it would be via pliers, and I'm a little edgy about clamping down and bending it.
This is what I used to punch the pins out:
