From "Try Ubuntu" run the installer, alt+f2 run gedit , type your custom mount point , select and copy the text to paste in the installer.
From "Install Ubuntu" you can't alt+f2 or run gedit so, go to system settings type your custom mount point in the filter box, select and copy the text to paste in the installer.
From "Try Ubuntu" run the installer, alt+f2 run gedit , type your custom mount point , select and copy the text to paste in the installer.
From "Install Ubuntu" you can't alt+f2 or run gedit so, go to system settings type your custom mount point in the filter box, select and copy the text to paste in the installer.
I can't explain more clearly , my English bad.