There's a pulley dealie that'll take up the extra cable that you need to get the brakes to actuate.
When you go to the LBS and ask for a " pulley dealie that'll take up the extra cable that you need to get the brakes to actuate", and they will cock their head sideways, jaw slightly slack, thinking about your worthiness to even stand on the floor in front of them, and then you will add "I believe they are called "roll-a-ma-jigs"'.
You will then think "What have I just said and how stupid do I look". BUT, the LBS will then give you what you want. I think they generally run $20 a piece. You will need one each, front and back.