Shut down Adobe Acrobat.
Run the installer downloaded from www.plda.net.
Go through the installation process.
When running PLDA for the first time you will be asked to enter an activation code. To run evaluation period please click "Evaluate (14 days)". 14 days trial period will begin. All features are fully accessible during the period. To use PLDA after the trial period, you will need to buy PLDA and enter the activation code.