I know it's not appropriate, but I really want these two models.
There's nothing I can do.I need some help.
The password issometimes provided by the model creator on the model's nico nico page. Sometimes there is a clue inside the video or it may even be spelled out right there for anyone who needs it to find. Try following the links, perhaps follow the creator on twitter, say hello to them, ask respectfully and maybe they will tell you. Unless the creator only wants to share the model with a defined group, they will have certainly left the password somewhere for you to find. The nico page link for the first model you list is below. You should take a look. good luck -spiritofrabbit
Each of that author's models is just the character's full name in katakana as the password. So just copy the name, and use a kanji to hiragana converter, then a hiragana to katakana converter. Also, be sure to remove any spaces between the characters.