Tokenized Booster Packs can be transferred to and from several external wallets, including Hive-Engine, Steem-Engine and WAX. While the packs cannot be opened when tokenized, they can be listed and traded on external markets.
Your Hive-Engine wallet is linked automatically because your Splinterlands account is also a Hive blockchain account, but you will need tolink your WAX wallet to your Splinterlands account to use this feature.
After clicking the CONVERT button on the MANA WELL (OPEN) page, a menu will appear that allows you to either tokenize or deposit packs to/from your various linked external wallets. It will also show you how many packs you are already holding in those external wallets.
Select the chosen wallet from the dropdown, specify the number of packs to move, then click TOKENIZEto move out of the game, or DEPOSIT to move into the game.