a) You would install cPanel/WHM on the first server, then
b) setup "remote MySQL" in WHM and enter in the details for the second server. This option is available under " Main >> SQL Services >> Setup Remote MySQL server" (https://x.x.x.x:2087/scripts5/remotemysqlhost).
If you have existing databases, you'll want to replicate them to the secondary server first. cPanel is licensed per-server, and licenses cannot be re-used for multiple machines with the current licensing model. Thanks!