Need help migrating from 1.0.2.1 to 1.5

I have a meteor app I built 2 years ago and is deployed on Heroku that I need to update. Unfortunately an update and git push isn’t working but what I did find is if I create a new meteor project I can push it to Heroku. So I think it’s time to upgrade from 1.0.2.1 to 1.5. But how do I do that? The files my app contains are:

client/flat-ui.min.css
client/flat-ui.min.js
client/lib/bootstrap.js
client/lib/bootstrap.css
myapp.css
myapp.html
myapp.js
public/[icons/images/fonts]

When simply copying all these files to a new meteor project I get errors at this line:

if (Meteor.isClient) {
  Router.map(function() {

ReferenceError: Router is not defined

What routing package are you using?

I’m not sure, here is what’s in my 1.0.2.1 .meteor/packages file:

meteor-platform
autopublish
insecure
markdown
iron:router
http

I think there have been changes with Iron router since then, might be worth reading the most recent docs there.