I'm assuming the RSU's were sold to cover taxes on the date of exercise or within a few days. there shouldn't be much of a gain or loss. the thing you missed is that the wages on your w-2 were increased for the value of all the RSU's exercised. example: say you paid $5 on exercise per share when the FMV was $30. $25 would have been added to your W-2 as compensation. that's part of your basis. in addition the $5 you paid is also part of your basis. so your total basis is the $30. since prices can fluctuate during the day you may have sold for $31 giving you a $1 gain per share or if sold for $29 you got a $1 loss per share. The $58K should be the sales price of the RSU's sold to cover your taxes. like I said previously get the basis from your company or it may even be on the 1099-B you should have gotten for the sale. the sale gets enter as a Short-term transaction on schedule D through form 8949. with amended return may also send along the 1099-B if it shows cost or letter from the company specifying your cost basis. with TT the amended return you prepare will have all the needed forms. as a minimum in addition to 1040-X there would be form 8949 and schedule D.
if you know how to enter the transaction you don't need a tax advisor. just make sure the schedule d makes sense. the sales price probably s/b the $58K and costs almost the same. so a small gain or loss.
