This assumes you have reviewed IBM GSKit (Global Security Kit) - Getting Started (command line) or IBM iKeyman - Getting Started (GUI).

Let's say you have a Key Database file named example.kdb. One way to interact with the Key Database file is to use the -pw (password) option, like this.

${install_root}/gsk8/bin/gsk8capicmd_64
-cert
-list all
-db /path/to/example.kdb
-pw your_password

Another option is to use -stashed (check out my article on stash password).

${install_root}/gsk8/bin/gsk8capicmd_64
-cert
-list all
-db /path/to/example.kdb
-stashed

Here is how you can change the password for the Key Database file.

${install_root}/gsk8/bin/gsk8capicmd_64
-keydb
-changepw
-db example.kdb
-pw <current password>
-new_pw <new password>