I'm looking to do just the opposite - switch mine from right to left. Word has it the usual way to switch it is to drill another detent spring hole offset to the left and "clocked" so it doesn't interfere with the original hole. Sounds to me like you could just switch it back.
Drop the trigger assembly and look at the top of the rearmost projecting part, above the safety. On a non-modified righty, there will be a 1/8" or so hole drilled down toward the safety offset to the right of center. Yours will likely have another hole close by, offset left. Push out the little cross pin at the top to release the spring, push the safety completely out, turn it around, put it back in, and put the detent ball, spring & cross pin back into the original hole.
In any case, let me know how it was accomplished. If it's a matter of swapping small parts, maybe we can arrange something.