A Reader Asks…

I have recently checked my credit report and I realized I had several credit card accounts which were unused for several years running with a zero balance for some time.
I would like to close them to resolve my accounts and improve my overall credit.
I have to admit that some of the credit companies are quite odd (not cititbank or MBNA) but smaller credit houses from obscure stores I once purchased something to earn the 10% off etc.
How do I go about contacting the credit card companies to close these empty accounts?