Go to "Transactions" on the lefthand side of your Puzzle account.

Find the transaction in question (make sure the date picker reflects the range you want to apply).

You can also filter by amount.

To delete the transaction, click the check box on the far left.

A "Remove" option with a trash can icon will pop up on the bottom of the page.

You can then choose to remove it.

If you can't delete a transaction, it might be because it is finalized (green check) or it is included in a reconciliation (Accounting / Bank Recs).

You'll need to uncheck the green check so it becomes blue if it is finalized.

If it is included in a bank rec, then you'll want to go to that bank rec and "Reopen" the reconciliation. Then go back and delete the transaction. You'll then need to redo the reconciliation.