Make backups of your files first.
For Melbourne 2014 (see above), the downloaded DDS File goes into:
Use Ryder's PSSG Editor to first Export All Files, copy the mod into the new folder where all the dds files have been exported to, then click Import All Files and save your new patchup_ot2.pssg
There are many already existing tracks mods, so that's why it's better 2 make it yourself. The reason these files are provided as is, is that there are many different track(s) mods already in use, and if members like them, but miss these two files in them, they can update their own mods this way, without having to ask my permission. It's "Open Source" 4 "do-it-yourself" mods!