How to change git account in Git bash?

Much simpler, as I explained in “How to sign out in Git Bash console in Windows?”:

git credential-manager erase <url>

Here

git credential-manager erase https://github.com

No need to remove the credential helper which is practical for caching user’s password.

Or (replace xxx wit the output of git config --global credential.helper):

printf "protocol=https\nhost=github.com" | git-credential-xxx erase

# Windows (2020-2021)
printf "protocol=https\nhost=github.com" | git-credential-manager-core erase

# Linux
printf "protocol=https\nhost=github.com" | git-credential-libsecret erase

# MacOs
printf "protocol=https\nhost=github.com" | git-credential-osxkeychain erase