Gulr Error 35729 how to fix?

Question

gulp.js

Help: no access to the port, how to kill old?
I run gulp
Uhoh. Got error listen EADDRINUSE
:::
35729
...
_listen2 (net.js:1252:14)
at listen (net.js:1288:10)
at Server.listen (net.js:1384:5)
at Server.listen (C:\test3\node_modules\tiny-lr\ lib\server.js:162:15)
at Gulp. (C:\test3\gulpfile.js:20:9)
at module.exports (C:\test3\node_modules\orchestrator\lib\runTask.js:34:7)
at Gulp.Orchestrator._runTask (C:\test3\ node_modules\orchestrator\index.js:273:3)
at Gulp.Orchestrator._runStep (C:\test3\node_modules\orchestrator\index.js:214:10)
You already have a server listening on 35729
You should stop it and try again.
events.js:160 thrower
; // Unhandled 'error' event
^
Error: listen EADDRINUSE 127.0.0.1:80
at Object.exports._errnoException (util.js:1036:11)
at exports._exceptionWithHostPort (util.js:1059:20)
at Server._listen2 ( net.js:1252:14)
at listen (net.js:1288:10)
at net.js:1398:9
at GetAddrInfoReqWrap.asyncCallback [as callback] (dns.js:62:16)
at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:81:10)
here is my gulpfile.js global.hostname = "localhost";
var gulp = require('gulp'),
sass = require('gulp-sass'),
autoprefixer = require('gulp-autoprefixer'),
minifycss = require('gulp-minify-css'),
rename = require(' gulp-rename');
gulp.task('express', function() {
var express = require('express');
var app = express();
app.use(require('connect-livereload')({port: 35729}));
app.use(express.static(__dirname + '/app'));
app.listen('80', hostname);
});
var tinylr;
gulp.task('livereload', function() {
tinylr = require('tiny-lr')();
tinylr.listen(35729);
});
tinylr.changed({
body: {
files: [fileName]
}
});
}
gulp.task('styles', function () {
gulp.src('sass/*.sass')
.pipe(sass({
includePaths: require('node-bourbon').includePaths
}).on('error ', sass.logError))
.pipe(rename({suffix: '.min', prefix : '_'}))
.pipe(autoprefixer({
browsers: ['last 15 versions'],
cascade: false
}))
.pipe(minifycss())
.pipe(gulp.dest('app'));
});
gulp.task('watch', function() {
gulp.watch('sass/*.sass', ['styles']);
gulp.watch('app/*.css', notifyLiveReload);
});
gulp.task('default', ['styles', 'express', 'livereload', 'watch'], function() {
});