A note of precaution for guys consider doing the shoulder mod. The blue suit fabric is very fragile, with the 'chainmail' pattern easy to rub off or show signs of peeling. So while you are trying to take the inner collar plastic out, try to minimize your pulling on the fabric (especially the trap area behind the neck) to minimum by opening up more stitches on the back, so there is less tension and more room to do all the pulling and prying of the inner plastic collar. Also, try your very best to keep the upper collar from separating from the suit on the sides and front. While you can always glue it back with super glue if they are separated from the suit, some of the 'chainmail' pattern will get ripped and won't match up anymore. The upper collar cover is your safe haven, as it is used to cover all the rips and glue mess you are doing for this mod, but if you ripped 'chainmail' outside of its covering area, you'll see scars on the suit exposed all the time. Keep that in mind.
If you want the suit to suffer minimum damage, you have to be extreme careful. Another option is to do what Tony did, rip all of the upper collar out and strip out everything (even let you move the collar down closer to the 'S' by regluing the collar rim lower and trim out any excessive blue fabric above the 'S', but in return, it will have a bunch of rip marks that you'll have to live with or hidden by the cape.
It is not an easy mod, and I am learning from people's feedback and my own little mistakes as I go, but it is looking good (got the inner collar out and re-glued most of the upper collar back in place, but still need more work). For those don't want to risk it, simply not do the mod, and just replace the cape with Tony's which will still improve the look.