How do I remove pimples from my upper back skin area?

Don't scrub. Please don't scrub your back! your skin is not a pot, it should not be scrubbed. In the long run that will only make your acne worse. Back skin is second only to the soles of your feet in thickness, so most of the time an oral medication is necessary to control it effectively. Topical medications have very limited efficacy on the back.
Acne. Many treatments for acne including topical and oral medications. See your doctor. A back scrub brush and soap are a good start.