Working on a M4 clone and recently picked up a side sling swivel off of EE. Just need to know how to install it properly to avoid canting the Front sight block. Can I do it without ordering the Brownells Orange puck? Any other options to support the front sight gas block maybe a piece of wood? ETA: Thinking about it more I couldn't really cant the sight.

Also one of the spring pin's that it came with won't even budge. I put some penetrating oil on it and I still can't get it to move. I need to get a flat punch, the roll pin punch is starting to damage the spring pin.

Help and Thanks  

I've seen guys do 'em in the field with a pair of pliers.

Not sure why yours are so tight; I've done them with a punch while just holding the upper.

Going to try a vise to support the piece to remove that stubborn pin.