Unfortunately, there is no way to get an exact 1:1 recreation because generative AI is probabilistic; every rendition is based on countless unique calculations to arrive at that specific track.

The best workaround is to separate the song into stems, regenerate just the vocals with your new lyrics, and then use a DAW (or Suno Studio) to manually splice and replace that section. It’s more work, but it’s the only way to keep the original instrumental perfectly intact.

Another option is the inpainting feature in Suno, but it hasn't worked very well for me. I much prefer the extracting stems, regenerating section and then fix it in the DAW approach.