This is a big job, if you have never done this before, it would be best to get someone there to help you.
1
You would need to first backup your files.
2
Create a bootable Windows 11 USB on an empty 8GB USB flash drive.
3
Then go into BIOS and disable CSM Support and enable secure Boot.
4
Then at the start of the installation, the drive would need to be converted from MBR to GPT
At the very start of the installation process, press Shift + F10, or Shift + Fn + F10 to open Command Prompt
Run this command and hit Enter:
diskpart
Run this command and hit Enter:
list disk
(Make note of the disk number you want to convert and enter it into the next command - replace X)
Run this command and hit Enter:
select disk X
Run this command and hit Enter:
clean
Run this command and hit Enter:
convert gpt
Then close Command Prompt and begin the installation.