Passport-Local Mongoose - Change password?

Looking at the source there is a function that is added to the schema called setPassword. I believe that after authenticating you can call it to change the password for the user.

schema.methods.setPassword = function (password, cb) {
    if (!password) {
        return cb(new BadRequestError(options.missingPasswordError));
    }

    var self = this;

    crypto.randomBytes(options.saltlen, function(err, buf) {
        if (err) {
            return cb(err);
        }

        var salt = buf.toString('hex');

        crypto.pbkdf2(password, salt, options.iterations, options.keylen, function(err, hashRaw) {
            if (err) {
                return cb(err);
            }

            self.set(options.hashField, new Buffer(hashRaw, 'binary').toString('hex'));
            self.set(options.saltField, salt);

            cb(null, self);
        });
    });
};

Good answer, but for ones who come from the MEAN stack (uses passport-local, not passport-local-mongoose):

//in app/models/user.js

/**
 * Virtuals
 */
UserSchema.virtual('password').set(function(password) {
    this._password = password;
    this.salt = this.makeSalt();
    this.hashed_password = this.encryptPassword(password);
}).get(function() {
    return this._password;
});

So this would change the pass:

user.password = '12345678';//and after this setter...
user.save(function(err){ //...save
    if(err)...
});