For configuring SSH to devices through remote access VPN terminating on the ASA ,
apply these commands globally ( if you are accessing the ASA on the VPN Client from the outside interface)
For more information, refer to Configuring Secure Shell on Routers and Switches Running Cisco IOS.
Refer to TFTP in order to download the recommended TFTP server.
Is the configuration exactly the same when accessing the ASA using SSH throgh a Site to Site VPN as well? (When the management servers are located on the other site of the VPN tunnel)