The budget way is to take city bus. Take bus 33 at Qinhaungdao Railway Station to Shanhaiguan South Gate then change to Bus 25 to the Old Dragon's Head. It would take over a hour. You mean you take train from Qinhuangdao to Shanhaiguan and then take a city bus or taxi to the Old Dragon Head. I think it is not necessary. Or you can take a taxi from Qinhuangdao Railway Station to your destination. Talk about the price with the driver and the taxi fare should be less than 50RMB. Additional replay for the train stop time. Generally you should get to the platform a few minutes earlier than the train arrives. When the train stops, you have 4 minutes to get on the train, so 4 minutes is enough, unless you can not get there in advance.