Building a helmet is pretty much the same thing regardless of were you got it from but if you follow the link above he also have videos of him building it.
You really shoulden’t have any foam. Idealy you would just be able to squezze your hand through the wrist opening. The maker if the armor (for the movie) had envisoned it to look as it had grown onto the body, keeping it form-fitting is the way to go for that iconic Stormtrooper-look
Hey
If I can make a suggestion it would be to either Ask questions in your thread or start one with that particular question. Reason I say this mearly to avoid ”extra work”. I already answered this question in your build thread some 11h ago
Jonas - I would like to welcome you to the 501st Legion and the Nordic Garrison Great job on that SDS suit and I hope to Troop with you one of these days
Rivet on the cod is not to be painted, it should be brass (screen accurate) or silver and 8mm However a rivet is not needed for approval, it’s a L2 requriment. As for ab button paint, humbrol nr14, french blue is a popular choice.