Monchengladbach: travel
You can reach Monchengladbach by train via Eurostar - it's two hours from London to Brussels, then a further 70 minutes to Aachen where you can change for a 50 minute final leg to Monchengladbach Hauptbahnhof, pictured below.

Welcome to Monchen... you know the rest: The main Hauptbanhof. Buses to the stadium leave from the other side of the tracks - so go back in and underneath.
Check out the Germany website for details - www.bahn.de. You can get London Spezial offers from 99 euros return if you decide to take the train and stay in nearby Cologne, Dusseldorf or Aachen - you can then get a suburban train to Monchengladbach when you need it.
The nearest airport to Monchengladbach (fed up of writing it out already) is the relatively minor Dusseldorf Monchengladbach, linked by Bus 10 which runs between the airport and the main railway station every 20 minutes.
The more likely option is Dusseldorf International Airport, 45 minutes away - the airport is on the main train line and it's one change in Dusseldorf to get to Monchengladbach. Cologne/ Bonn airport could be considered, but would be more than an hour away by train.
I didn't stay in town overnight, where hotel options exist but are limited. To be honest, you can just as easily get to Monchengladbach on the train, with Dusseldorf, Cologne, Duisburg and Aachen offering thousands of hotel beds all within an hour.
It's unlikely you'll need to make use of transport in the town but if you do, the bus station is handily placed next to the train station and a good chunk of services pass through this and the Alter Markt.

The bus station outside the train station. Tip: If you're looking for buses to the stadium, most of them leave from the other side of the train station so go back and through the station to the other side.

