If you're running the beta(v1.7.0.2 and up), you can use the new "Convert a Variable Value" action to do this directly.
Otherwise, you'll want to use the "Set an Integer Value" action; Select the "Convert Text/Token" option, and enter the name of your variable embedded in the "{SMALL:}" token.
E.G.
Set integer [myVariable] value to the converted value of {SMALL:myVariable}
Though, I'd recommend using integer values in your profile as well, as small integers offer no real benefits, and are set to be deprecated at some point.