Praise be to Allaah.
Praise be to Allaah Who has guided you to His Straight Path. I ask Allaah to make you steadfast in following it. As for this tattoo which cannot be removed except through this kind of surgery, you do not have to do this, because it is too difficult and will cause pain and hurt. Allaah says (interpretation of the meaning);
“… and [Allaah] has not laid upon you in religion any hardship…” [al-Hajj 22:78]. Your regret and dislike of that, and your determination never to do it again is sufficient. Also, Islam wipes out what came before, so in this case leaving it as it is should not cause you any harm, in sha Allaah. May Allaah help you to do that which He loves and which pleases Him.