Mobile Joomla update

I have Mobile Joomla version 1.2.3 and 1.2.4 is out. I have done some edits in core file (mobile_iphone/index.php).
If i do update will they be gone?
Where can I look for change log?
Can i version update manually (replacing specific files)?

Update overwrites all MJ files. I'd recommend you to rename pacthed template (e.g. to mobile_iphone2), then you can use it and update MJ without side effects.

Where can I find changes from 1.2.3 to 1.2.4

www.mobilejoomla.com/mobile-joomla-blog/180-mobile-joomla-124-and-mobile-joomla-pro-126-released.html
Note "Improved Mobile Menu module" section.

Thanks a lot.