You cannot download 2.7.0 directly from Yamaha’s current website. Yamaha only hosts the version (currently 2.9.x or 3.x depending on region). Here’s what happens when you search:
The .n27 (Instrument Info) file is the digital fingerprint of your keyboard. Version 2.7.0 now exports this file more accurately, ensuring that the compiled expansion pack does not exceed your specific keyboard’s memory limits. Yamaha Expansion Manager 2.7.0 Download
Here is everything you need to know about downloading, installing, and using YEM 2.7.0. You cannot download 2
Managing "Instrument Info" files and memory limits can still be a bit technical for casual users. Where to Download Yamaha Expansion Manager 2.7.0 Download