Hi, the only way to really remove the gas to avoid venting to atmosphere is to reclaim it. This involves hooking the fridge up to a reclaim pump and a recovery tank. The pump will suck the gas out of the fridge and pump it into a tank. It's not really something you could do yourself without investing in the equipment to reclaim it which costs a fair bit of money, far too much for a one off job really. Another option would be to contact a local refrigeration/air con repair shop who maybe happy to do it for you for a small cost, how much they would charge I have no idea but it shouldn't be too much as the amount of refrigerant in the system will be tiny.
Sorry I couldn't come up with a free fix but reclaiming is the legal and responsible way we do it really. Having said responsible way, the laws in many countries are a bit daft regarding this as the base gas in most modern fridges is usually found in aerosol cans as the propellant and millions get vented everyday. A bit of a hot topic in some circles.
edit... just read your post a bit better, there is no way to remove the fridge workings without disturbing the gas.
Sorry I couldn't come up with a free fix but reclaiming is the legal and responsible way we do it really. Having said responsible way, the laws in many countries are a bit daft regarding this as the base gas in most modern fridges is usually found in aerosol cans as the propellant and millions get vented everyday. A bit of a hot topic in some circles.
edit... just read your post a bit better, there is no way to remove the fridge workings without disturbing the gas.