Last updated on January 15, 2018. In the expansions for Rail Raiders Infinite, the page inserts gave two options on how to incorporate the expansion cards and train cars into the core game.
The first option "is to replace original cards and cars with train cars and cards from [the expansions] before you start playing. When you make this swap, you must remove all of one type of card or car and replace them with a type of card or car with an equal number of cards. So, to use a Loot card from [the expansions] that has two copies, you must remove an original Loot card that has two copies."
The second option is to "add all of the cars and cards from [the expansions] to their respecitve decks and just play with larger decks and a bigger pool of train cars."
Below, I have compiled a master list of the train cars and cards to help facilitate swapping them out.