The 7.1-r2 is mainly a bugfixes release of 7.1-r1:
This release contains four files. You can choose one of these files depends on your devices. Most modern devices should be able to run the 64-bit ISO. For older devices with legacy BIOS, you may try the 32-bit ISO.
To use an ISO file, Linux users could just dump it into a usb drive to create a bootable usb stick like :
dd if=android-x86-7.1-r2.iso of=/dev/sdX
where /dev/sdX is the device name of your usb drive.
Windows's users can use the tool Win32 Disk Imager to create a bootable usb stick.
In doubt, try the 32-bit files for legacy BIOS devices and 64-bit files for UEFI devices. Please read this page about how to install it to the device.
Except the traditional ISO files, we also package android-x86 files into a Linux package rpm. It allows Linux users to easily install the release into an existing Linux device with a standalone ext4 root partition. On an rpm based device (Fedora/Red Hat/CentOS/SUSE...), just install it like a normal rpm package:
sudo rpm -Uvh android-x86-7.1-r2.x86_64.rpm
This will update your older installation like 6.0-r3 or 7.1-r1 if you have.
On a deb based device (Debian/Ubuntu/LinuxMint/...), please use the alien tool to install it:
sudo apt install alien
sudo alien -ci android-x86-7.1-r2.x86_64.rpm
All files will be installed to the /android-7.1-r2/ subdirectory and boot entries will be added to grub2 menu. Reboot and choose android-x86 item from the menu to boot Android-x86. Alternatively, you can launch Android-x86 in a QEMU virtual machine by the installed qemu-android script:
Note Android-x86 running in QEMU and the real machine (after rebooting) share the same data sub-folder.To uninstall it :
sudo rpm -e android-x86
sudo apt-get remove android-x86
repo init -u git://git.osdn.net/gitroot/android-x86/manifest -b android-x86-7.1-r2
repo sync --no-tags --no-clone-bundle
Read this page for how to compile source code.