Search the forum, there are a few topics which tell you what to do. Basically you need a program to convert the .dds files and a program like photoshop. Hoppah's files need unlocking as well and there is a topic that tells you how to do that.
Read the last few pages of the topic for that map. Other people have asked the same thing. You just have to put the files in the LA mod v1.8 folder instead of LA Mod v1.7