1. Take Backup
2. Uninstal Tableau Server
3. Install Tableau Server 9.3.6
Note: When you install the newer version of Tableau Server, use the same drive and directory that the earlier version used. This way, data and configuration settings from your earlier version can be automatically imported. If your installation location is not the default, see Upgrade Tableau Server to a Non-Default Location.
For futher information reffer to Perform the Upgrade
Initially I had located the Tableau server 9.0 in a PC.No will there be any issue if I install the latest version in another PC?
And how to take Back up any steps/process?
First you have to check the HW specifications in the system on which you are installing.
Min 8GB RAM is required and 15GB HDD space is required.
stop the tableau server
You have to take the backup of all the reports and users
clean the database
Uninstall the tableau from the system
Install the new version server
Install new tableau desktop
restore all the backup
start the server