Once here we are going to create the installer with the ISO image that we already have on the Mac and on the option: ISO Image We select the Windows 10 ISO and on the destination disk we select our USB. Now let's go to Launchpad> Others and we open the Boot Camp assistant. Once we have everything ready, we carry out a backup of our Mac with Time Machine or similar to avoid problems of any kind with our data and information if something goes wrong. This can be found on the Microsoft website but it does not contain the license, it must We must acquire it to make it work.
Now the most important thing is to have a 16GB USB for Windows 10 with all drivers required and then download the Windows 10 ISO file. The first thing is to be very clear about the requirements to carry out the installation and these are: have the version of OS X updated to the latest version available, have at least 2GB of RAM and have about 30GB of free space on the hard disk or more depending on the tasks to be carried out in our partition with Windows, the more space the better since this cannot be modified later.