It's quite simple. Send the BTC in your localbitcoins wallet to your blockchain wallet address.
You may have given the seller your blockchain wallet address, but the seller wouldn't have sent it there. Once the bitcoins are released from escrow, they're sent to your localbitcoins wallet automatically. So just send those over to your blockchain wallet. Easy.
THANK YOU; you're right - that was easy (just did it.)
BUT... now it says "unconfirmed transaction" over in the blockchain wallet. Is there something *I* must to do confirm? Or is this something the "system" does and I have no control over that part?