Update Content Type

var ctypes = listTeam.ContentTypes;
context.Load(ctypes, ctys => ctys.Include(c => c.FieldLinks, c => c.Id, c => c.Name));
context.ExecuteQuery();
string GUID = "";
foreach (var item in ctypes)
{
    if (item.Name == "Item"){
        GUID = item.Id.ToString();
        break;
    }

}
var contentType = ctypes.GetById(GUID);

context.Load(contentType, ct => ct.FieldLinks);
context.ExecuteQuery();

var fields = contentType.FieldLinks;
foreach (var fld in fields)
{
    if (fld.Name != "Title" && fld.Name != "DocType" && fld.Name != "Categories")
    { fld.Hidden = true; }
}

contentType.FieldLinks.Reorder(new string[] {"Categories", "Comments", "Created", "DocType","Modified","Reviewer", "Title" });

contentType.Update(false);
context.ExecuteQuery();