On the Chrome app on your computer Open Ledger Manager and download the BCC-BCH app on Ledger device.
This may require you to delete other coin apps, but keep bitcoin, add BCC. Once it's on the device/Ledger:
Open the Bitcoin Cash application on the Ledger device,
Open the Bitcoin Wallet Chrome app
Select Settings / Blockchains / Cash / Split
Click on Receive, write down the address : I usually copy it and paste in email or google doc temporarily...
Copy the address and then go back to the BCC Wallet app page
Select Settings / Blockchains / Cash / Main
Click on Send, paste the wallet address, and send to this address.
Give it a minute then you will have the two apps on the Ledger : BTC and BCH (Cash), and you will have an equal amount of BHC as you had BTC. Comprende ?