> ## Documentation Index > Fetch the complete documentation index at: https://help.descript.com/llms.txt > Use this file to discover all available pages before exploring further. # Replace Script Track > Swap sections of your script with a new video or audio file. Replace script track is for finishing a project you roughed in with placeholder audio. Start with a [scratch script](/ai-speech/write-mode) and a rough recording or [AI Speaker](/ai-speech/tts) voice, lay in your B-roll and music, then swap in your final recording when everything's in place. Once you swap in your new audio, Descript will align it with all the other audio and video elements in your [composition](/working-in-projects/overview) — even if the new media is differently timed or an imperfect match. With Replace script track, you no longer need to wait for the final voiceover or recording to start creating in Descript. ## How to use Replace script track 1. Select the section of your script with the new video or audio you want to swap in, then right-click and **Copy**it. 2. Select the section of your script that you want to swap out with what you copied, then right-click and choose **Paste special > Replace script track**.\\