Ok this is very simple but I am feeling generis to day so i will tell you here rather than just posting a link to some tutorial.
Step one
Make your mod.(pretty obvious)
step two
Put your mod into an MPQ(if you don't know what that is than I am sorry)
step three
open MPQdraft
step four
click on the create self extracting MPQ button or press M key.
step five
Give your mod a name.
step six
browse to the location of the MPQ you made in step two
step seven
browse to the location you want the .exe to be saved to then click next.
step eight
click on the Starcraft icon in the top box then click on the Starcraft icon in the bottom box and click next.(i know its a lot of clicking)
step nine
if you don't have any plugins to configure or don't know what that means than just click finnish and your done.
I hope that helps