Redoing Ascendancy

Definitely important that you need to complete the same tier of trial as the highest you’ve completed on that character. So if you only have 2 asc points, then you can change ascendancy with the first trial, but if you have all 8 asc points, you’ll need to beat trial master or Zarokh again.

Not true at all. Look it up on the wiki or YouTube so you don’t miss any steps, but you only have to remove all ascendancy points, and inside the final reward chamber for Sekhema the vendor allows you to respec

Not sure on current carry prices, but at the end you can speak to the sekhema npc and refund your current ascendancy points, then interact with the altar to change ascendancy and use your points

Just change them at doryani. Unless you want to change the actual ascendency and not just the points. Then I believe you need to do a run again

Steps: 

• enter Trial that can award at least as many Ascendancy points as you have (so if you have 2, you can use any Trial, if you have 8, you need to beat Zarokh or Trialmaster)
• complete Trial successfully
• respec at Balbala or Trialmaster NPC to remove all Ascendancy points (so your unspent points should read 2/2 or 8/8 or whatever, and no nodes are allocated in you Ascendancy tree).
• go to Ascendancy altar (where you get points), and you can freely choose your Ascendancy just as if it was your first time. 

Your non-Ascendancy points don’t matter at all, and you don’t need to respec until the end of the Trial.

I did this before. Just refund all ascendancy points before doing the trail (make sure same tier you had done before). After beating the trail, you have an option to choose new ascendancy again.