Well... Then I was saying guiding I mean if you could do something like this "Images> Modes Indexed color>???" I am not so good then it comes to follow instructions on ps.. ^^'
Exactly that.
If it's giving you that error, that means the new PAC file you just made was bigger than the original PAC file you have.
The solution?
Use less colors in your textures.
What's highly recommended is, as VILE said, making some objects grayscale (that drops file sizes by quite a lot in these situations)... making some objects transparent (going into the Alpha Layer and making them disappear by coloring it all black or white, depending on the texture)... and then, there's manually reducing the amount of colors used in the textures.
Doing this is rather simple, if you've ever messed with +1 or +2 textures.
~Find a texture you want to drop the quality of.
~Go to Image -> Mode -> Index Color...
~Make the Index of the color relatively low (like 200, 100 colors even, if you're desperate for it, or don't mind the quality change

).
-The texture's quality should drop, and the texture is now Indexed.
~Now simply go back to Image -> Mode and select "RGB Mode" (I believe that's the name of it), and the texture will revert back to edit-able RGB mode, but keeping the Index quality of 100-whatever colors.
~Save, and you've got a quality-dropped texture.
~Rinse and repeat for any others, if you want.
Hope that helps some.
