There are two ways to forcibly move AI: through path_corner entities or choreography. Choreography goes beyond the scope of this document and will be ignored. We shall instead focus on path_corners, which are simple: make one, name it, then shift+drag it to create the next path_corner in the chain.
To manually make a chain (or link one up in a circle), edit the 'Next stop target' property. Note that the 'Train Speed' values are obsolete unless you are making a path for a func_train.
Once you have the path laid out, go to your AI entity and set 'Target Path Corner' to the path_corner you want it to enter at.
Note that the example map does not have any info_nodes. They are not needed to have AI follow a path.