Sometimes the most tedious part of replacing or repairing a shower fixture is getting the old tape off the threads. Teflon tape acts as a seal for threads and prevent them from leaking. Most often you see Teflon tape around showerhead and shower arm connections, as well as tub spout connections. Sometimes the tape can be peeled off with your fingers, but other times, removing Teflon tape in a shower requires more effort.
Scrub the male threads of fittings with a stiff wire brush. The wire brush will scrape off the Teflon tape without harming the threads.
Wrap a damp rag around the threads tightly, and rotate the rag back and forth over the threads. The moisture loosens Teflon tape residue. Wipe away the residue with a dry rag.
Wet an old toothbrush, and brush the threads of female fittings. Female fitting are threads inside a fixture.
Wipe the inside threads with a damp cloth, and follow with a dry cloth.
Ensure that all threads are dry before you wrap new Teflon tape over them.