At the moment there is no possibility to delete any Private Wallet permanently. You may move private wallets to archive and recover it if necessary. To archive your Private Wallet, use the following steps:
1. Go to the Funds tab.
2. Tap on "Private wallets" in the Funds screen
3. Tap on the private wallet you would like to remove. Make sure to tap on the wallet name and not on it's balance
4. Tap on the Archive wallet button to remove the wallet from the list of visible wallets.
In case you decide to start using your archived Private Wallet, the following steps will help to recover your Wallet
1. From the Private Wallets tab, open the Archived wallets list
2. Tap on the pop up menu next to the wallet you would like to restore
3. Tap on the Recover wallet button.
If you archive a private wallet with positive balance, it's value will be reflected in the Total Balance. Please note that you may not remove the default BTC private wallet.