Europe - Vostock lake drilling.?

Last I read they planned to seal off the probe and then the probe would go through a sort of self-cleaning, whether chemical or with immense heat to kill any potential microbes. Once the probe was sanitized it could be lowered into the lake to collect samples in sealed containers. If scientists can ensure the probe is completely sanitized before it touches the lake's water, and then ensure the samples are completely sealed in an impenetrable container until it reaches laboratories until it can be opened in a clean environment, they can ensure that the sample isn't tainted. How they would return the probe to the surface is a different story. I imagine it would require literally reversing the process of the penetration. Guide the probe back near the originally-drilled hole via radio communication, and using heat to melt back into the ice, allowing the ice to freeze and seal behind the probe.