1. Double click the wallet:-
2. Hit backup this wallet & select 'export key list':-
3. Set it up something like this:-
4. Copy the private key:-
5JHB8C 9zkrKU CFg4Mg dHHg8x N9fzrn DFmka4 RhhK9a 3Zzu4j 7pu
5. Remove all spaces:-
5JHB8C9zkrKUCFg4MgdHHg8xN9fzrnDFmka4RhhK9a3Zzu4j7pu
6. Head over to blockchain, go to the 'import/export' tab, then paste the private key into the 'add private key':-
Hey-look, it matches!