Going from High G to Low G - Do i need to mod the nut?

As the title suggests. The nut slot for the G string looks like its shaped for specifically a high G. Can i just slot a wound low G string in there?

If not, what do i need to do and how?

I believe you should. You don't have to, but if you don't the low G will sit too high and may buzz or lose tone.

I have these great sets of needle files I found at a woodworking store, it consists of a handle and several files, round, 3 corner, square, flat, etc. All the files fit into the handle. The smallest round one is perfect for a low G.

If you don't have something like this, you can take some sandpaper and fold it over a playing card, and sand the slot. You might be able to wrap the sandpaper in a round toothpick and go back and forth. It would be best if the slot was round shaped, like the string. Try not to go any deeper, just enlarge the width of the slot. You will still be able to go back to high G. Smooth any sharp edges, especially at the mouth of the slot.

One final note, low strings do require a slightly higher action because the width of their wavelength is wider. So don't go too low. But most ukes have high actions to start with.

If you use the thinner flourocarbon low G you won't have to. At least I never have.

Jude

Never had a problem . . . .

Using the Worth non-wound Low G, I have never had to make alterations on the nut or saddle.
–Lori

I would try before making a modification. I have ukes I switch between high & low with no issue.
One thing to check is if the low G binds in the nut slot, it will make tuning difficult. Usually some dry-slide or pencil lead dust will make the string glide.
If you file the nut slot you may creat a problem if you ever want to go back to high G.