We have two ways.
1. Download ready profile from link below
2. Create new profile or modify your existing profile. With the source file where all sectors of the game discovered and the edit your game.sii
! Please be careful and make a backup of your game profiles before starting

Files created in May 2024 and can be outdated later (Actual in August 2024 before 1.51)

Text Source File with 100% discovered sectors https://sharemods.com/pjq3g86hrrjv/ets2_full_may_2024_trucksim.txt.html
Ready profile I created. Just download, unzip and put in your profile folder https://sharemods.com/y6v2mg9hk3j1/747275636B73696D5F6D61793234.zip.html

Tools mentioned in video: TS SE https://forum.scssoft.com/viewtopic.php?p=1060834
7zip https://www.7-zip.org/
Sublime Text https://www.sublimetext.com/