It has been a long time since its release Linux Mint 20. Finally, the team distribution development published instructions for the update. The remarkable thing is that this time you can only upgrade the Mint 19.3 64-bit.
Users running the 32-bit distribution are not so lucky.
The reason for this change is obvious, since Linux Mint 20 is based on Ubuntu 20.04 LTS, and both operating systems only exist in 64-bit versions. Linux Mint 19.3 is the latest version which supports 32-bit architecture and will be available until April 2023.
If you are satisfied with the current installation of Linux Mint 19.3 and you don't need to upgrade to version 20 since you can use with better safety your current operating system for a year or two.
Otherwise, you should take a look at the detailed guide below
How to upgrade to Linux Mint 20
The steps include a series of recommendations, e.g. to create one system snapshot with the TimeShift application. It also requires the installation of a new package, mintupgrade.
The other steps are standard and will be familiar to friends of the distribution.