You will treat your immersion as on any two-day Yom Tov (see our discussion below).  There should not be any problem of discrepancies between what you and others do, since mikveh preparations are private and many women prepare at home anyway. When you get to the mikveh, tell the mikveh attendant that you are still keeping Yom Tov so she does not expect you to pay. Make arrangements to pay after Yom Tov.

You do all your preparations prior to Yom Tov. Keep your hair tied back over Yom Tov to prevent as many tangles as possible, and try to avoid sticky substances and situations that could result in chatzitzot. You can eat normally on Yom Tov, including meat.

Since it is Yom Tov and not Shabbat, you can wash one part of your body at a time with warm water, liquid soap, and no wash cloth. You should also clean your teeth as permitted on Yom Tov. (There are several opinions about how to do this. We follow the position that you use liquid toothpaste (not gel) and pre-cut dental floss. If flossing would definitely cause your gums to bleed, then use toothpicks or a rubber tip instead of floss.)  At the mikveh, run your fingers gently through your hair to remove tangles, and check yourself to assure that there are no chatzitzot.  You may wet yourself prior to immersion either with one extra dunk in the mikveh or with a shower (check with the local mikveh attendant).

Chag sameach!