Below is the illustrated guide:
1) Go to resources root page:

2) Go to any folder where *.pcr files are stored and press "Extract all links" at Link Gopher plugin icon:

3) Then select all links to *.pcr files and run "DownThemAll! Selection" from context menu

4) Press Ctrl+A, right click mouse and select "Check selected Items", then "Start" button

5) Profit! *.pcr files are downloading with download manager. Repeat that for all links at stage (1)

Little trick in the end: If you need to import all pcr's at once you can move them to C:\Program Files\Ace Lab\PC-3000\Bin\DBUpdates and press "Find DB updates" button in PC-3000 software.