Follow the same steps under Mint DAI and Add but instead, you will check off the below tab to deposit collateral such as wBTC.
By doing this you will receive both rrToken and rcToken.
See how to trade rcToken for DAI (a loan) here:
See how to pay back a loan with your rrToken + DAI here:
See how to unwrap rrToken + rcTokens to recieve your collateral back here: