1. Sign out of xbox live
2. Reset your rank
3. Get the Private First Call achievement
4. Go back to dashbord and sign back into xbox live (make sure you are in the dashboard and not the game) so the achievement registers
5. Delete All rainbow six 1+2 memory
6. Delete your gamerprofile
7. Recover your gamerprofile
8. You should now have the Private First class achievement and your current rank