What I’ve been taught is to start from the bottom, change every other string in the bottom octave one at a time.

I’m with Briggsie, you certainly can do them all in one day if you have time. I usually change the wires first because they’re the least fun (for me) although they do hold their pitch sooner than other strings. When changing wires, be sure you give each wire at least an octave (preferably an octave and a half) of slack because they don’t stretch like other kinds of strings do. Otherwise you won’t have enough length to get enough windings around the tuning pin and when you try to bring it up to pitch, it’ll break.

As for the rest, it doesn’t matter whether you start at top or bottom. As you change each string, tune it up to pitch and retune every other new string, too, just as Briggsie suggested.

String changing time is a good time to gently dust each lever with a soft little brush before installing the new string.

New strings in the 1st and 2nd octave often come with enough length for two or three uses. For the longer 3rd, 4th and 5th octaves, consider saving the old string if it isn’t too worn, along with its anchoring string tie. Put each one in the packet that held the new string and keep them in a box marked “used,” so you’ll have an emergency backup for temporary use. (I don’t recommend saving old wires; they sound really dull and they’re generally too short to re-use after you take them off, although I know some who have done it.) It is ideal to keep a complete set of new strings on hand if you can afford it. (If not, ask for them for Christmas or your birthday!) Keep them safe from temperature and humidity extremes, just as you do your harp.

There’s no reason to wait between each string change. I found it easiest to take about 3 or 4 strings off at a time, string them through the top of the soundboard, tie the anchor then thread through the tuning pin and pull it up to pitch right away. Then do the same to the other strings.

I don’t really understand why you have to pull the pitch up slowly, unless the board is fragile and there’s a possibility of it ripping. If the harp is in good structural condition, the strings are nylon, gut or wire wound, there’s no reason to delay in pulling the strings up to pitch right away.

Just ran this by my HarpTech and he said if you’re really slow at changing strings, you should take them off one at a time. This will keep the board more stable. If you’re fast at changing strings, then you can remove more strings.

What brand of Gut strings did you use?