To delete a wallet from Koinly, select the 3 dots next to the wallet, and select 'delete'.
This will delete the wallet and all transactions in it.
Keep in mind! Deleting a wallet cannot be reversed, so if you need to re-import the wallet/exchange again, you will need to select 'Add wallet / exchange' and import your data again.
Once a wallet is deleted, any transactions that have been merged into transfers will be unmerged, as all transactions in a deleted wallet are removed.
Archiving a Wallet/Exchange
If you want to remove your wallet from your view only, and want to retain all of your wallet's imported transactions, you can select 'Archive' instead of delete. The wallet will then be moved to the bottom of your wallet list, but it can still be unarchived, accessed, or synced if needed.