First off, make sure you have the exact rom for your cart, most make sure it's the same region, and add it to your G6 lite
secondly, boot up with your passsme device and then when you get the the G6 lite's menu it is safe to swap in the game of your choice, in this case jump stars
third, look for the rom in your list of roms and highlight it and hit select on your DS, look for the option "DS Card > Default"
This will replace the current "Jump Stars.0" which has nothing unlocked with your own which as you stated has everything unlocked
thats's it, you can now powerdown, put your passme device back in and away you go, with your saves now
hope I helped