How to consolidate a large amount of unspent outputs? I have tried different solutions to consolidate a large amount of unspent outputs, but I am stuck:
1st option: Create transaction using "coinb.in/#newTransaction". But I need private key to create transaction and I am cant find option to export private key. There are steps given on support site for new and classic blockchain.info wallets. But I do not see option of "Private Key" when I click on Manage - More Options.

2nd step: there are some steps showing transfer/sweep funds - which I have tried but it did not work.
To consolidate coins to a single address, just send a transaction for the entire amount stored in your wallet to a new address. You shouldn’t need any outside tools, just use the wallet software to send a transaction to yourself.

You should pretty much never enter your private keys into an online website/service. Access to your private keys could allow that service to steal your coins, there is very seldom a reason you should need to trust someone else to not rob you of your bitcoin.