Either a good walk from the Hbf or bus 212 to the Auto Museum stop and then onto a bridge across…read morethe river. The folks here were very helpful and beware they do not speak any English. The campsite is very peaceful next to the lake and during the two nites which I stayed, it was quiet in terms of other campers, many in fact seemed to be long term stayers.
If you do not want to tent camp, they offer these tube cabins. The bathrooms were very clean and the hot water was very hot. Only cash is accepted, and 1/2 euro is needed for the showers, wifi is offered by Wifi Wolfsburg.