If you have data you want to remain in the calendar you should :
Take a backup of the database or ( better ) the whole installation ( luxcalendar folders on the server ) should be copied to your PC ( in case something goes wrong ) .
When this is done, then you simply install the version 4.7.7 "over" the 4.7.6 ( make a full upload of the 4.7.7 with "overwrite" )
The first time you then start the calendar it tells you that it is upgraded - and that is it.
Upgrading this way takes seconds - 20 seconds to download the installation ( this is just in case.. ) and 20 seconds to upload the new installation "on top" of the old.
Installation of the sqlite version takes seconds to install and seconds to upgrade. The beauty in the sqlite installation is that you have it all in the installation - easy to install, upgrade and eventually move to another server - all this takes seconds
If you only have testdata in your 4.7.6 then you could remove the whole installation and make a new installation with the 4.7.7
If you make an upgrade the side panel is not automatic set - you have to do this in settings.
If it is a new installation the side panel is set to be shown ( this is the default by new installation ).