Just to make sure we're on the same page, you're talking about Evilbay item #320891361633 correct? I ask only because there was another set of 6011A's available through a couple days ago that was 24V *AC*, rather than DC. But it looks like you're reading straight from the label, so it sounds like you're fine (with the adapter you mention).
It comes with the DIN connector that's identical to the one in this how-to thread: http://www.barrreport.com/showthread...-6011-solenoid
Just follow the instructions and ignore the ground connection, and it doesn't matter which socket you screw which wire into (for DC).
Somebody who actually has one of these specific units (I know oldpunk78 does) could provide more feedback.
*edit* or, yeah, you could just splice the wires together. A wire nut would be even easier than soldering.