If you have an existing file and need changes you'll need at least one or more of the following:

• InDesign or Quark document
• Unflattened Photoshop document
• New information to insert
• High resolution photos or logo
• Any information pertinent to the dimensions of the design. It would be helpful to specify if the files requires a bleed as well.

Here's an overview of what updating your design includes:

• Resize or rescale
• Add or delete text
• Add photo(s) or graphics
• Change fonts to a different style
• Change color scheme.