If you are using Bitcoin Core 0.12.0 or 0.12.1, you can go to Help > Debug Window and click on the Console tab. Then type in the box at the bottom
abandontransaction aaddeaa91cc7ed77b58044fa274cd6abaa0dd46b90f42a5bf05ab052775e0f28
If it doesn't give you an error, you should then be able to respend the inputs spent by that transaction.
So I did that, and didn't get an error. The full amount is back on the main screen. The transaction is still there though, is it always going to be there? I haven't resent anything and now I'm not even sure I want to or even should. Is there any way to clear the transaction from the wallet?
Thanks.
It should remove itself once the transaction drops from the network, although I'm not entirely sure. To clear it from the wallet you need to use
. It's okay to leave it there and it won't affect your wallet.