Saturated charcoal can be regenerated (de-saturated if you will) by applying a vacuum to it for a period of time. In the factory setup, fuel vapor goes in, then gets pulled back out via vacuum.
In a garage setting, this could be accomplished with one of our popular small electric compressors that has intake and exhaust ports. Instead of leaving the inlet open, connect it to the (otherwise sealed) canister and leave the outlet open.
I have done this with charcoal many times in laboratories. Works on most anything that has saturated the charcoal as long as the substance has a reasonably high vapor pressure. Obviously the outlet will need good ventilation to avoid excess accumulation of flammable vapors: connect a tube to it and route to a safe, well ventilated area, like outdoors.