Tangem cards are completely independent from your phone. All you need is the card, and you'll have access to your XRPL account(r-address) and funds.
The procedure couldn't be simpler. Either go to the "Switch account" menu (upper right corner of the home screen):
... or go to Settings (gear icon in the lower-right corner) > Accounts and tap the " + " sign in the upper-right corner.
Now click the Add Tangem card button:
When prompted, hold the Tangem Card against the back of the phone and wait for the app to move to the next screen.
You now imported your Tangem card again. Your transaction history, as well as the ability to send funds and sign (by holding your card against the back of your phone again).