wish to get couchette on eurail amsterdam to munich?

Question

where would i go first (bonn, cologne?) Then which city in Germany from there/prefer overnight train from Belgian to Germany night of 1/2 or 3/08.

And could i go thru Luxembourg to do this?

Answer 1

This is a job for the German train planner, and indeed, it can find what you ask for. (See source, English language for German train planner.)

There is basically one direct train from Amsterdam to Munich through the night, duration of the journey a little less than 11 hours. Leaves at 20.32 and arrives at 7.16.

There are several connections where you change train, and the train with couchettes you will be in for 4 or 5 hours.
You can not yet book for August, but the planner can give you timetables.
There is one connection that runs Amsterdam, Maastricht, Liege, Hannover, Munich, leaving Amsterdam at 21.37 and arrive in Munich the next day at 10.40. But you will need to change trains at just past midnight and again before one in the morning and at 6 in the morning.

I would go for the direct train.

PS.
I also looked for a connection via Luxembourg, but that did involve two more changes and a lot more travel time.