3👍
You can only overwrite a cookie if you use the same parameters (i.e. Domain, Path, Secure, and HTTPOnly).
So to overwrite your current cookie, you need to set it from the same domain and path.
1👍
If the match is present and unique, this works to set expiration to end of session:
document.cookie="meteor_login_token="+/meteor_login_token=([^;]*)/.exec(document.cookie)[1]+";path=/"
Source:stackexchange.com