STEP 1: Open the template file in Adobe Illustrator (version CS and above).
Make sure that the artboard has the exact dimensions you have ordered. If the dimensions are different then change the height and width properly to fit the exact dimension.
STEP 2: Use [My Artwork] layer to create all your art.
STEP 3: Outline all Fonts. Go to Type -> Create Outlines.
STEP 4: Delete the Instructions layer before creating PDF.
STEP 5: Save File as Press Quality PDF and set Standard as PDF/X-1a:2001.