Welcome the Technical Support section. Help us in assisting you by providing us with a concise and descriptive elaboration of your issues. Be specific and if possible, provide us with a step-by-step instruction in replicating your problem.
Starting the Upgrade
Uninstall the older JomSocial version by going to Extensions > Extensions Manager, select Manage, select JomSocial/Community, click Uninstall. Make sure that all JomSocial related modules, plugins, extensions are uninstalled.
Go back to 'Install', upload the JomSocial installation package and follow the onscreen instructions (press 'next' a lot).