4.4.5. Minimal system upgrade
In some cases, doing the full upgrade (as described below) directly might      remove large numbers of packages that you will want to keep.  We therefore      recommend a two-part upgrade process: first a minimal upgrade to overcome these      conflicts, then a full upgrade as described in 
Section 4.4.6, “Upgrading the system”.
To do this, first run:
# apt upgrade --without-new-pkgs
  
This has the effect of upgrading those packages which can be upgraded without      requiring any other packages to be removed or installed.
The minimal system upgrade can also be useful when the system is tight on space      and a full upgrade cannot be run due to space constraints.
If the apt-listchanges package is      installed, it will (in its default configuration) show important information      about upgraded packages in a pager after downloading the packages. Press      
q after reading to exit the pager and continue the      upgrade.
4.4.6. Upgrading the system
Once you have taken the previous steps, you are now ready to continue      with the main part of the upgrade.  Execute:
# apt full-upgrade