Upgrade guides are available for:
Upgrade Scylla from 4.1.y to 4.2.y on Red Hat Enterprise Linux and CentOS
Upgrade Scylla from 4.1.x to 4.2.y on Ubuntu 16.04
Upgrade Scylla from 4.1.x to 4.2.y on Ubuntu 18.04
Upgrade Scylla from 4.1.x to 4.2.y on Debian 9
Upgrade Scylla from 4.1.x to 4.2.y on Debian 10
Scylla Metrics Update - Scylla 4.1 to 4.2