I can not attend Neilah due to COVID virus restrictions. Which prayers in the repetition of chazan can I say since the arc is open for the entire duration of the repetition? Thanks

Shalom, Thank you for your question. When praying alone (at any time, not just on Yom Kippur) the parts of the service that require a minyan cannot be said. With that in mind – one cannot say Barachu, Kaddish, Kedusha, the Torah Reading (from a scroll with the blessings), the Haftorah Blessings before and after, nor the repetition of the Amidah. Therefore, Neilah (at the end of Yom Kippur) when said without a minyan will start with Ashrai and U’va LeTzion, then, without the kaddish, the silent Amidah. After the Amidah one could go straight to the Avinu Malkainu’s, and then end with accepting the yoke of Heaven by saying the Shema (once), Baruch Shem (three times) and Hashem Hu HaElokim (seven times). If the correct time has come and you have a sofar you could then blow it, and in any event then say “L’Shana Ha’Ba B’Yirusaliiyim”. After this, one would pray a normal weekday Maariv, then make havdallah and break the fast. However, if you so desired (and there was time), after your silent Amidah, and before the Avinu Malkainu’s, you could say any or all of the slichot that are part of the repetition of the Amidah. Keep in mind that without a minyan one does not say the blessings of the Amidah as the chazan does in his repetition (you already said them in your silent Amidah). One can only say the additional slichot – for example “Petach Lanu Shaar” or “Ki Anu Amecha V’Atah Elokainu...”. That is, all the parts that are not the blessings of the Amidah. When saying them, one also has to make certain that when saying the 13 attributes of Hashem (“Hashem Hashem El Rachum V’Chanun...”) one either reads them with the musical notation as when reading from the Torah, or does not say them, and just skips over them. This is because they require a minyan – unless they are being read as purely Torah verses (with the trop) and not as a standalone prayer. I hope this is clear and of some help. Feel free to write for any more information. Blessings.