Hi Barak,
the question you are asking is a loaded question. Meaning it could be as simple as saving the MPP files through the plug in to Clarity (but see this very unlikely), or you might need to do XOG.
The problem lies that MSP and Clarity do not have the same data integrity rules, therefore, importing particular parts will involve some manual mapping.
I have done this type of project a couple of times in the past and what we had to do was sort of a hybrid approach. Some XOG, some saving through the MSP plug in.
You have to keep in mind that might cause you additional Grief:
Resource teams (make sure they are exact matches, both resources and roles)
Actuals, how do you plan on bringing actuals in to Clarity
All task dependencies. Cross project dependencies are the biggest pain (so make sure all your project shells are created first if you have cross project dependencies.
....
Feel free to reach out to me if you want more details, and i will dig up my notes from those projects. I have no problem sharing that with you.
Cheers
Federico
fpena@itroisolutions.com