[VAC] Sticker Removal

[SushiLuver]

Hi,

I�m trying to remove the large number stickers that are above the front and 
back windows of my �74 Airstream.  I�ve got most of the sticker material off, 
but the adhesive residue still remains.  What is the best way to remove it 
without damaging the metal skin of the trailer?

Doug
Burbank, CA