מותר ליטול צפרנים לא שנא דיד לא שנא דרגל ופירש ה"ר יהודה דוקא בסכין אבל לא במספרים והרב ר' ברוך מוסיף לאסור אפילו בסכין ולרב אלפס התירו אפילו במספרים ולזה הסכים א"א הרא"ש ז"ל. כל רפואה מותר בח"ה:
It is permitted to cut nails (on chol hamoed) whether the fingers or toes. And R' Yehudah says only with a knife but not scissors. And R' Baruch adds it is even forbidden with a knife. And the Rif permits even with scissors and my father the Rosh agrees. All healing is permitted on Chol Hamoed.
מותר ליטול צפרנים בין דיד בין דרגל אפי' במספרים: הגה אבל יש מחמירין ואוסרים וכן הוא המנהג להחמיר שלא ליטלן בין בסכין בין במספרים אם לא לצורך מצות טבילה שנוטלן כדרכן בחול: (סמ"ק ותוס')
It is obvious that anyone who can shave can cut nails. And it seems to me if they were cut on the eve of Yom Tov you can cut them on chol hamoed because Rabbeinu Tam even allows one to shave in this case as the Tur writes.
Even with scissors - And forsure with a knife or the hand
Some are strict - Because they hold that here too one should not enter the holiday disgusting. He should plan things out on the eve of the holiday. And all those that can shave can cut nails. And if he cut nails before the holiday he can cut on chol hamoed because some even allow shaving if one shaved before the holiday. And even though we do not hold like this... here one can be lenient because many are lenient in any case.
With a knife - but with hands or teeth it is muttar. One who cuts nails with his teeth, it is not considered disgusting.
מֻתָּר לִטּל שָׂפָה בְּחֻלּוֹ שֶׁל מוֹעֵד. וְלִטּל צִפָּרְנַיִם וַאֲפִלּוּ בִּכְלִי. וּמַעֲבֶרֶת הָאִשָּׁה שֵׂעָר ... בֵּין בַּיָּד בֵּין בִּכְלִי. וְעוֹשָׂה כָּל תַּכְשִׁיטֶיהָ בַּמּוֹעֵד. כּוֹחֶלֶת וּפוֹקֶסֶת וּמַעֲבֶרֶת סְרָק עַל פָּנֶיהָ וְטוֹפֶלֶת עַצְמָהּ בְּסִיד וְכַיּוֹצֵא בּוֹ וְהוּא שֶׁתּוּכַל לְקַפְּלוֹ בַּמּוֹעֵד:
It is permissible to trim one's mustache on the intermediate days of the festival, as well as to trim one's nails—even with an instrument. And a woman may remove hair ...whether by hand or with an instrument. And a woman may engage in all her usual cosmetic treatments: She may paint her eyelids, she may remove unwanted hairs, she may put rouge on her face and she may apply lime and that which is similar to it [onto her skin]. And [the latter is] so long as she can peel it off during the festival.