Q:

switch from SSH key-based authentication to normal account login

The current login method of the server is SSH key-based authentication, I wish to switch it to normal linux login by key in username and password. i understand this is unnecessary, but i have to switch it over. How to do it?

A:

Look inside of /etc/ssh/sshd_config
change lines
PasswordAuthentication
PubkeyAuthentication

!check other options / lines so you don't lock yourself out. If you want to be sure, post your config file here and ask back beforehand.
If the machine is connected to the internet and the ssh port is accessible, you should take this as a warning that you don't fully understand ssh configuration.

