Dukman
I thought the Vault-Tec DLC gave us the ability to do that already? At least I read somewhere that it does. I have yet to look into it yet.
Also, might want to take a look at this one as well. Combine that mod with this mod.
According to "Oxhorn", once you assign a task to one of your settlers, that settler will remain assigned to whatever task you assigned him/her to do even if you remove the asset in the assignment. Such as assigning a settler to guard duty and then scrapping the canon or guard post. Even though the canon and/or guard tower is gone, the settler is still assigned that task and won't do anything else like roaming around and generating income in the form of caps for you. According to good old Oxhorn, this mod allows you to remove a settler's assignment. Since he needs that mod for this I take it that it isn't available in the game's regular menu.
Here is a nice buildup of Spectacle Island that I had stored in my bookmarks. As far as I remember there is no foul language in it and I don't think he needed a mod to unlock the size cap.