‘Access Hollywood’ has learned that Britney Spears will guest star on the CBS hit ‘How I Met Your Mother’. What role will she play? A receptionist. Britney was on the set Tuesday rehearsing for the role which is being filmed later this week. An Us Weekly reporter added that the show told Britney the door is open if she wants to continue to appear on the show. Video of the segment at MSN has since been removed.