A few 2-Step questions
My setup is for a stick car with a micro switch that is activated when the clutch pedal is all the way down( I can't see why this wouldn't work with a brake pedal)
So how it works the line lock button and clutch switch, are wired through a toggle switch to two relays that wire into the 2 step and a red LED light that is mounted under the shift lite.
When the toggle switch is turned off the the line lock is only activated.
When the toggle switch is on you press the line lock button to activate the first relays which in turn activates the 2 step, the clutch switch, line lock, and red LED that tells you the system is activated. The second relay is turned on by the clutch switch(or brake switch in your case) at that point you release the line lock button. Once the clutch switch is released the relays turn off and does not turn on again till you push the line lock button to reactivate the relays circuit again.
Kind of a long explanation but is been working flawlessly for me for like 12 to 15 years now. All it cost is two 4 prong relays, a toggle switch , a micro switch( you already have the line lock switch), few different colors of wire and a small red LED lite or your color choice.