Remove the lid and front of the piano and place your lamp so that it lights the strings. The outer casings of some pianos come away in several pieces; you may want to remove these to give yourself more room to work. Leave any casings that hold the keys in place.
Tighten or loosen the tuning pin on the note in the middle of the keyboard, known as middle C. Turning it counter-clockwise or left will lower the pitch. Turning it the other way will raise it. Pitch it by listening to a tuning fork or electronic tuner. Some keys have three strings so using your rubber tuning wedge, block off the sound for the other strings so that only one will sound. Strike the key firmly as you turn the tuning pin using the wrench until the sound matches the tuning fork or the electronic tuner.
Tune the next 12 notes going up and going down the keyboard from middle C being careful not to turn the strings too quickly. Remove the wedge to tune the other strings. Tune pins in several stages, resting the string for a few minutes between each turn. Tune the rest of the notes, continuing to work out from the middle.
Set the tuning pins so that they do not slip out of tune. To do this, tighten the string slightly above pitch, then loosen it by an even smaller amount. This takes practice and will get easier the more you do it. Pianos tuned by novices will need tuning more frequenty.
Replace broken strings with new piano wire. Cut the wire to the appropriate length and wind around the tuner pegs. New strings take time to settle so expect to tune the string several times. Broken strings can be fixed by tying a piece of new wire to the old wire and stretching it onto the peg.
Repair piano hammers by opening the top of the piano and removing any dust or debris. Use a screwdriver to loosen any hammers that are out of place and screw back into line. Glue any broken hammers back into place and allow to dry before playing the key.
Repair a broken piano key veneer by gently removing it using a chisel. Sand the wooden base of the key before gluing a new veneer on top. Plastic veneers are widely available but traditional ivory keys are more difficult to get hold of and may have to be salvaged from an old piano which is no longer playable.
Repair sticking keys by sanding the part of the key which is rubbing. Press the key and listen for a scraping sound to find out which part of the key needs to be sanded. If the key is getting stuck because the casing or piano rail has warped seek expert advice.