Usually, you don't have to care about importing your old profile, credentials, templates, etc. because LDAP Administrator performs import of previous version configurations automatically upon installation.
However, if you have decided not to import your data automatically during the installation, or you have to import the old configuration from a back-up after the current version has been installed, follow the instructions listed below.
Importing version 2.X configurationMake sure you've closed all the instances of LDAP Administrator 2008.
Execute Start->Run->cmd.exe to run the command line prompt.
Go to the application root folder. e.g. cd C:\Program Files\Softerra\LDAP Administrator 2008
Execute the following command: mbmt.exe /importV2
Importing version 3.X configurationMake sure you've closed all the instances of LDAP Administrator 2008.
Execute Start->Run->cmd.exe to run the command line prompt.
Go to the application root folder. e.g. cd C:\Program Files\Softerra\LDAP Administrator 2008
Execute the following command: mbmt.exe /importV3