Next open the _Opticals_ entry of the navigator. A list of all marker points will appear. Drag these markers onto their respective limb they belong to. This is a crucial step, so make sure to correctly assign the markers to the correct part of the actor. The mapping can be changed later, if you experience troubles with the animation. After you are done, it will look something like this:
Please keep in mind, that you can only assign up to 5 markers per body part.
Now rotate and scale your actor and its limbs such that the cubes are in the position that the markers were on the captured person. It is important to be as precise as possible here since small deviations might lead to weird looking results. It is advisable to have photographs of the person whose motion was captured (in the best case you have a photo of all marker locations of the person making a T-Pose during that mocap session). After you are done, it might look something like this:
