Ruger won't touch a weapon unless the entire weapon is shipped, and it has to be in stock condition. They will remove all aftermarket accessories from your rifle and make it stock again before they return it to you. Of course it all has to do with legal liability on their part, and they basically can't send you back an aftermarket rifle. Actually before you ship it they instruct you to not include anything that wasn't on the rifle when you purchased it, and that they are not responsible for lost articles. It is almost guaranteed that they won't ship the accessories back because in some cases they just give you an entirely new rifle. Don't sell your original factory stock (or factory anything for that matter) in case you need to service your rifle.
This is a serious problem if you have done any major work or changes to your rifle, like an aftermarket barrel swap for example. I understand where Ruger is coming from, and the blame can be heaped on their lawyers. As usual they complicate something that should be straight forward and simple.