Great guide. Thanks!
Tip for best results:
See the Youtube video by Alexander Kurz. Video is not in English but it is very demonstrative and easy to follow through.
Do not replace with CR2032. Replace with the ML2032 battery only. If you are not able to get it from local shops or in your country, you can always buy it online from AliExpress.com (sister website of Alibaba.com - a very reputed site). I recommend to purchase 2 batteries rather than one, just to be on safer side, but AliExpress does have option of return/refund if your newly purchased battery doesn't work.
Another warning and tip:
For those of you brave enough to try the CR2032, you can find an iFixit guide to open the keyboard and permanently disable the solar cell connections, so the CR2032 can be safely used in the K750. (Do not just cover the solar cells as that is not recommended at all).
Logitech K750 Keyboard ML2032 to CR2032 battery replacement