Question about Tilesets

I am creating a cinematic campaign called Second Genesis. It includes some light modelling and skinning. So far, everything has gone up operation and the Intro will be posted on maps.worldofwar.net perhaps in the near future.

However, for Chapter 1, it is vital that I can use a wood plank tileset I've found on this site. The creator of the wood plank tilesets is trying to help me place the tilesets into my maps, but I have had no success. I will continue to ask him questions, but can any of you post a full, detailed procedure of how to replace tilesets with new ones taken from the Internet?

What kind of tileset is it, the double one or single one?

Well heres an example on how to replace Ashenvale Leaves tileset.
Rename the custom one Ashen_Leaves.blp then import it into your map with path TerrainArt/Ashenvale/Ashen_Leaves. Then goto modify tileset and check custom tilesets. Then replace an exist one or add the Ashenvale Leaves tileset. Then it should work.

If u cant you can pm me or sumthing and i can help more.