Note that the images are usually xz-compressed make sure to uncompress them with unxz. Download the image for your ARM device and ensure that the checksum matches the one provided on the website (see Section 2.1.3, 'Verifying Integrity and Authenticity' for explanations on how to do that).Since these images are available, your task of installing Kali on an ARM device is greatly simplified.
They provide these images pre-generated, ready to download on their website: To make those devices more accessible to Kali users, Offensive Security developed scripts to build disk images that are ready for use with various ARM devices. Kali Linux runs on a wide variety of ARM-based devices (laptops, embedded computers, and developer boards, for example) but you cannot use the traditional Kali installer on these devices since they often have specific requirements in terms of kernel or boot loader configuration.