The 3M remover is better for hardened or old adhesive. It's a fairly strong chemical, and not really necessary if the glue isn't hard. Citric-based or ammonia-based products are usually all you need. Windex with ammonia will work as well as anything. Spray it on and just let it work for a few mins to soften the old adhesive. Hold a couple of paper towels in one hand and kinda scoop the snotty mix into the paper towels with a squeegee. The citrus and ammonia stuff will clean up with a garden hose.