How do I get duct tape off vinyl siding,the sticky stuff?

I PUT UP PLASTIC OVER THE OUTSIDE WINDOWS,USING DUCT TAPE. DUCT TAPE LEFT STICKY STUFF ON THE VINYL SIDING.

How do you get sticky residue off vinyl siding?

The people that lived in our home before us used those little double sided sticky squares to hang hooks for their christmas lights in the shape of a tree on our vinyl siding. How do you get the sticky residue off without haming the siding?

Removing sticky backed numbers from metal siding?

I bought my first house and it has cheap sticker numbers attached to metal siding. I would like to remove the numbers but how do I do that without damaging the paint on the siding?
Thank you.