Sproket removal?

[tankaray]

So I had my frame crack on my old cruiser and I am putting the motor on a new bike. I cant figure out how to get the metal piece inf front of the sprocket off. It is more than likley really easy but I cant figure it out. I have a Picture showing what I mean.

 

[biken stins]

Its tight. Hold the brake arm steady turn nut next to it counter clockwise. I use a piece of pipe that fits over the arm to hold it.

 

[cabinfever1977]

you are supposed to loosen the nut while its still on bike.

 

[HoughMade]

The one that holds the arm on? Don't think so- it would be behind the dropout.