What is the easiest way to re-number vendors?

When the AP vendors were originally setup, they didn't leave enough space for additions.    I'm considering re-numbering.  We have hundreds of vendors.

I'd also like to number any duplicate vendor in different companies with the same numbers.

What would be the easiest way to go about this?   I'm hoping there's another way besides using the delete and change vendor utility.  I believe I'd have to go through each and every vendor using this utility unless I"m mistaken.

Thanks.