A mod launcher capable of connecting to the modrinth api i.e. Modrinth app or Prism launcher
A Pc that meets the minimum requirements.
download the modpack.
lauch your compatible mod launcher (compatibility list below)
Import the file into the laucher
launch the modpack
Note this may not possible between major versions.
Instructions:
navigate to your old minecraft folder and copy your the file called "options.txt" and the folder "config"
In your new minecraft folder paste the "options.txt" and the folder "config".
If it asks to overwrite files select no
start your game and your options will remain