In Logic, with your session open, go up to File>Export>Project as AAF. It will then show the choices for 24 bit vs. 16 bit, sample rate, etc. Keep it as whatever it is currently.
Choose a destination to save it (the desktop, your audio drive, etc.). It will take a few minutes, and then when it's done, you may have two folders. One will be the name of the project/AAF, and the other folder will be audio files for it.
Very important: You must drag the folder that says AAF into the Audio files folder (or vice versa), or Protools will not be able to find everything correctly.
Once you've done that, you can open it in Protools. There are at least 3 ways to do that.
1. Go into that folder, and click on the icon that says AAF. If Protools is not open, it will launch Protools
2. If Protools is already open, go to File>Open>and then find the AAF icon in that folder just like in step one.
3. Go to File>Import>Session Data>and again, find that AAF icon.
Regardless of which method you open it with, the first time you do this, the Import Session Data window will open. You will have choices, besides all the audio tracks, you will have choices as to anything like automation, etc. It's probably easier to uncheck most of that (in the lower right column), because assuming you are wanting to mix it, you will be starting from scratch anyway.
Then continue on, and it will import the tracks to where they need to be in the timeline.
Note that you will only need to do this the first time. When you save your session, you can just save it as a Protools project, and from then on just open that and use it.
Note that doing it this way does allow you to, if you needed to, keep some things like any automation that was done. If you don't need any of that, it may be just as easy to do what was suggested earlier, which is, in Logic, click File>Export>All tracks as audio.