Skrill is using BitPay and blockchain is not supporting BIP70. So the steps would be the following:
1. Go to your skrill account => Deposit => choose Bitcoin and the amount you want. You'll be redirected to the page to make a payment.
2. Copy the link and paste it here:
https://decoder.bip70.org/3. In step 2, you'll be given the address and the amount you should pay. Go to Blockchain.info and send to that address.