For supported versions, it does not cost anything to download from the Download Station, and it looks like the asset in question is also available there as well which will save you time and money.
It is at the moment until next September. In terms of getting hold of the asset, use the link provided by BuilderBob and search for the KUID he listed, or use Content Manager and search for Asset KUID: (kuid) - (kuid) is either of the versions given by BuilderBob.
If you are unsure how to use Content Manager, see my sticky thread in DLS,FCT regarding downloading using that tool.
Here's a direct link that will download it into Content Manager: trainz://install/<KUID2:44090:4512:41> (note: this is a special link type that only Content Manager is meant to be able to open). Once it's in Content Manager, click the Start button in the top left panel and wait for it to download.
well now I downloaded the complete island of sodor route from SI3D and its has 295 unknown KUIDs, god damnit, is there a way to get all of them at once?