This is done very easily!
There might be some other ways but…
For the first button (that will enable the others and disable itself)
on(release/press/whatever) {
if(_root.firstbtn) {
<what it is supposed to do>
_root.firstbtn = false;
}
and put an action _root.firstbtn = true; into some frame in your movie …or somewhere
And you can disable/enable the other ones as well the same way you disabled this one (note that to enable _root.<variable> = true; you have to change “false” to “true”)