Restring

• For a nylon-string guitar, tie one end of each string at the bridge using a double loop. Thread the other end of the string through the hole in the tuning key roller at the other end of the guitar. Bring the end around the roller, under the string and make a loop. Tighten the string with the tuning key until it makes a note rather than a noise. Then follow the same procedure for the other strings.
  
  

Retune

• Looking at your guitar from the front, the strings need to be tuned, from left to right, to E, A, D, G, B and E. The lower E is the one below middle C. The higher E is 2 octaves above the lower one. Use pitch pipes, a keyboard, or another tuned guitar to produce the right notes. Turn a string's tuning key to tighten the string until you achieve the correct note.
  
  

Replace

• On older guitars, a machine head, or tuning peg, sometimes breaks, so you can't tune up properly. Whether you will be able to get away with replacing one head, or an inline strip of three or more depends on the design of your guitar. Either way, first slacken and remove any strings in the way. Then unscrew the broken head, or inline strip. Insert any press-in bushings that came with the new part. Use the supplied mounting screws to attach it. Refit the slackened strings and retune them.
  
  

Repair

• If your bridge is coming loose on an old acoustic guitar, it might be because you have steel strings on a guitar made for nylon strings. Steel strings exert considerably more tension on your guitar than their nylon counterparts. First, slacken and remove the strings. Lever off the bridge carefully so you don't do any damage. Some people prefer to use hide glue but luthier John LeVan recommends Titebond. Position and clamp the bridge with padding so as not to scratch your guitar, then restring and retune when dry.