Submit your opponent when he tries to footlock you.
Transition to a leg drag when your opponent defends the footlock.
Use the belly down footlock when your opponent defends the straight footlock.
Jason Takemura teaches the Lins lock counter against a opponent who is attacking the legs.
Ken Ledesma teaches the footlock counter to the berimbolo.
Jason Takemura teaches how to finish a belly down foot lock when opponent defends.
Jason Takemura teaches how to enter into single leg x guard and finish with a straight foot lock.
Sweep > Outer Bolo > Back Choke
Sweep > Outer Bolo > Back > Armlock
Berimbolo variation from footlock position.