Delete Free Style reader data for return

Hello, how I delete the data from a sensor that I have to return;for problems with it.
After a long time using it, he began to fail with the strips, claim and send me a new one (without any cost).
They tell me that I must deliver it, but erasing all the data, hence my doubt.
Thank you very much, greetings

Hi @tenerife72 cannot be done without ABBOTT help or do they.
You send it as is and that they delete it.