Custom interface icon..

How can I make a unit have a custom made interface icon?

I'm tried using wc3 image extractor II to turn my TGAs into BLPs, but when I specify the blp file in the interface icon line at the world editor, it shows up right in the editor, but in the game it's a green square.
I've never tried this before so I'm probably not completely understanding the sequence. Can anyone explain how to do it?

did you inject your new icons into the map?

uhm how do I do that? I have the .blp file in the same folder as the map.. but how do i inject it?

mpq2k.exe

make sure your map uses the default loading screen or the files won't preload the first time someone plays your map.

So.. what do I have to do exaclty?
I have this w3m map, and this blp file, and mpq2kGUI in a folder. And now?
How can I make the unit have the blp file for interface icon, and make it compatible with computers of my friends too?

you need mpq2k dos also, put everything in a same folder, then in the first line of the gui, put the name of the map
the second line is the name of the file you want to inject
the third line is the path where the file would usually go in the mpq
then press Run MPQ2K and voila

Still doesn't work.. I see a green square instead of the icon. Should the third line be an existing path of a file in the to overwrite in this w3m? (for instance replaceabletextures\commandbuttons\btnarthas.blp)
I tried this, and for the arthas hero I used the default icon (that's the one that should be modified, right?) but it's just a green square :(
I also tried non existing paths.

I have in the first line:
map.w3m
In the second:
btncustomhero.blp
In the third:
replaceabletextures\commandbuttons\btnarthas.blp


In the folder running from I have mpq2k, mpq2k GUI, map.w3m and btncustomhero.blp


What is wrong? Has it something to do with preloading files?

your problem was that you took that a bit too litterally when he meant 1st line 2nd etc..

from what you got presuming its all in the same folder go to dos prompt easyiest or make a btach file

you would type in the following:

mpq2k.exe a map.w3m btncustomhero.blp replaceabletextures\commandbuttons\btnarthas.blp

now that should be all one line with spaces between the each string. The letter a is used to add or "inject" info in to the map you specified "map.w3m" then the name of the file that you have created, must be in same folder then the path where it will go when you use the map. Remember sometimes that if you run the game from within the W.E. it will not show the graphic, don't stress just close the WE completely and open the map from within the WC3 game itself

LOL it works now..
With the mpq2k GUI it's three lines in a windows interface, the tool only puts them together in one line like the one you mentioned.. that wasn't the problem. I suspect my blp file was just damaged or actually a different file type with the blp extension somehow. I recreated the file and now it works. Thanks all.