In my opinion either do it 100% accurate, as @cetera says above, with attention to detail as a "we want to deliver the whole package" with correct instruments, outfits and stage moves, or do it as a tribute to the music only, where you play the songs but don`t bother to look or perform like the original. No point in doing it halfway. Most of the tribute bands I`ve seen have been pretty good, with The Likeness and The Jamm being two that stood out for musical delivery.