Instructions
Call a trash and recycling provider. Ask if it accepts cassette tapes for recycling and where to drop them off. If it doesn't provide this service, ask if they know of any cassette recycling programs in your area.
Donate your cassettes to a local thrift store or non-profit organization. Many organizations like Goodwill and The Salvation Army will accept these donations for resale. All donations made to Goodwill and The Salvation Army can be written off for tax purposes. Ask for a receipt if you choose to donate them.
Locate a national media recycling service. Many of these agencies can be found online (see Resources) and will take your cassettes for free. The only cost is the price of shipping your cassettes to them.