Isn't that a part of the attraction of bitcoin? You can AVOID tax?
And as for "realized gains", why not just sell your bitcoins offline to some person willing to show up at a coffee shop and pay cash?
All these threads about "how do I pay tax" sound like a cacophonous symphony of masochists screaming "Rape me! No, rape me first!"
Paperwork is painful enough. Why add to the misery?
Or at a minimum, why not just only sell back an amount equivalent to your initial investment and keep the BTC? The next time you take a holiday, or step out of the country, you can probably cash in some of your BTC and stay under the radar and avoid more paperwork.