How to Replace Ubuntu With Kali Linux?

Kali Linux is an open-source, Debian-based Linux distribution generated to deal with information security which includes penetration testing, computer forensics, reverse engineering, cybersecurity, and security research. Kali Linux was developed by the well-known information security organization offensive security. it was mainly designed for penetration testing and digital forensics. Kali Linux offers various features as an operating system, which are:

• Multi-language support. 
• Full customization of Kali ISO
• Live USB Boot
• Kali NetHunter
• Over 600 penetration testing tools pre-installed
• Developed in a secure environment
• Free (as in beer) and always will be Wide-ranging wireless device support
• Custom Kernel, patched for injection
• GPG-signed packages and repositories
• A Trustable operating system
• Forensic Mode
• Kali Linux Full Disk Encryption
• Kali Linux Metapackages
• Kali Linux accessibility features

Kali Linux have more than 600 penetration testing tools pre-installed, they all have different features and uses in the field of information security;

• Information gathering tools: these tools help the pen-tester to gather valuable information about the user or the victims, It is a method used by analysts to determine the needs of customers and users. there are many information-gathering tools like NMAP, ZENMAP, DNS tools, Searchsploit, stealth scans, and LBD tools
• Vulnerability Analysis tools: these tools help the pen-tester to determine the weakness that a particular target system or victims have so that they can sure those systems for better security. for example, CISCO tools, CISCO auditing tools, etc.
• Password cracking tools: these tools help the pen-tester to crack passwords through various authentication systems with ease, tools like Hydra, Johnny, John the ripper, hash Cat, etc. used for password cracking.
• Exploitation tools: An exploit is a piece of software, data, or sequence of commands that takes advantage of a vulnerability to cause unintended behavior or gain unauthorized access to sensitive data. exploitation can be performed once a vulnerability is identified. tools are, Metasploit, BeEF (Browser Exploitation Framework), Armitage and, Linux exploit suggester. 
• Forensics tools: The forensic process is used as part of data recovery processes to gather data from a crashed server, failed drive or reformatted operating system (OS). tools are, p0f, pdf-parser, Dumpzilla, and DFF (digital forensics framework).

Install Kali Linux in Ubuntu:

• Go and download the Kali Linux disk image (ISO file) from kali.org.
• Download the win32 disk imager tool to write the Linux image on a USB drive.
• Write the image to a USB drive: plugin USB drive and open the disk imager tool and specify the path of the ISO image you have downloaded, now click on right.
• Shut down your computer and turn it down again while pressing the boot menu key (you can find your device boot menu key by simply googling it).
• After the boot menu appears select boot from a USB drive and hit enter.
• Now you should be able to see the Kali Linux installation window, click on start the installer or install.

• Select the language → location is optional → choose the keyboard layout and continue.

• Configure the network (not necessary now)→and simply select eth0 and continue. (if these windows come in installation)
• In the next step, do not configure the network now and continue.
• Give the hostname to your computer→ now decide a strong password → to continue.

• You can configure the clock.
• Now the main part is the Hard drive configuration: after these steps, all of your previous OS will be deleted.
• Select the Guided-use entire disk → to continue.

• Select your main storage probably the bigger partition (storage)→ continue.
• Then go with the recommended settings→ and continue.
• After you see this window hit continue and select yes to write changes to the disk. (after this step your data will be deleted so do it carefully)

• The main installation will be started, and it will take some time.

• Now you should decide yes if you are connected to the network or else No.
• The package manager will be installing updates for Kali Linux. Choose software you want to install otherwise go with the recommended.

• Installation must be completed by now → to finish installation hit continue.

• The system will reboot automatically, and you can now remove the USB drive.  Do not skip any of the above steps you might end up getting nothing.
• Installation steps may vary with the version of Linux you are installing.