i went through the massive headache of doing this recently, and ended up finding a solution after hours of searching, the tool that's commonly suggested is "MCC tool chest" and it's awful, you can only find the most recent version via archive.org and it doesn't convert chests properly, as well as turning a lot of blocks like lilypads and seagrass into dirt
the one i found that is much, much better and properly converts worlds is called "je2be", it has a web app that takes forever to convert:
https://je2be.app but it works properly, alternatively it has a microsoft store version which is pretty fast
https://www.microsoft.com/store/productid/9PC9MFX9QCXS
with this one you don't need to extract the save file with horizon/explorer 360, it'll just take the raw bin file from the USB stick and do the rest, only bug i've encountered is that it doesn't convert the worlds to infinite and will just extend the world with stone, without the borders, you'll need to edit the world with a world editor to reset the chunks outside the map boundaries, map graphics are also a bit messed up but can easily be reset by deleting the map files