Sounds easy right?
Not so fast!
The state of the state is that how exactly to do this is yet to be defined.
This means for TinCan adopters, our recommendation is to hold fire for the moment.
See also:
https://github.com/adlnet/xAPI-Spec/issues/170
If you read through this thread, you can see its pretty much TBD at this point although Rustici does have a recommendation.
Also:
https://github.com/adlnet/CMI-5_Spec_Current/blob/master/cmi5_runtime.md#content_launch
https://github.com/RusticiSoftware/launch/blob/master/lms_lrs.md
