HaloMods "Classic" Read-only Archive

i need some help for add new map previews on mainmenu (i'm a mainmenu n00b )
i use BatchDeswizzle for get my screenshots from H2 because UberScreenShotTool doesn't works
when i get my screenshots are in .bmp format (i'm pretty sure that u know it )
how to use these for mainmenu?
(mainmenu previews are in .dds, also i'm pretty sure that u know it)

Thanks.

Search Button is your friend.
Here is one of the like 3 tutorials.

Thanks!!!!
XD, i'm a little n00b into this page