Edit APP buttons

Hi every one
Is it posible to edit application buttons ( 10 of them ) if yes pls let me know as to HOW.
I did try to open the buttons in Picture publisher and paste a small icon on the button and save it . The icon shows on the button Alright but the originality has changed.
I mean earlier the button was showing OK but now the button has a SQUARE white background also. This gives the feeling as if it is focefully there, Any soultion
thanx in advance

You edited the gifs without maintaining the transparency.

Hmm well how do i do that .. i have tried with transperency 0% and gone all the way up to 99 % and still the same... no change ... Any suggessions

I don't know how to do it in your program.