Make sure to back up your game files before overwriting them.
Run RDAExplorerGUI.exe to extract *.rda files.
(Optional:) If you want to save your changes back to an Anno 2205 or Anno 1800 *.rda file, you must afterwards also update file.db (located in maindata), else the game will likely crash on start. For Anno 1800 this tool also allows to generate checksum.db (located in maindata). file.db and checksum.db must be in sync.
Run FileDBGenerator.exe
Select the location of you maindata directory.
Specify where to save the new file.db, and possibly checksum.db. Once again: Make sure to back up your original file.db before overwriting it.
Click Generate and wait for the process to complete.
Changelog
RDAExplorerGUI
Remember last extraction location (#13 - thanks, @FroggieFrog!)
FileDBGenerator
Can generate checksum.db file (required when making changes to file.db in Anno 1800)
Generated file.db is much closer to the vanilla one, in terms of format. Makes it less likely the game will crash.
Make sure to back up your game files before overwriting them.
Run RDAExplorerGUI.exe to extract *.rda files.
(Optional:) If you want to save your changes back to a Anno 2205 *.rda file, you must afterwards also update file.db (located in maindata), else the game will likely crash on start:
Run FileDBGenerator.exe
Select the location of you maindata directory.
You can deactivate some *.rda files, or reorder them.
Specify where to save the new file.db. Once again: Make sure to back up your original file.db before overwriting it.
Click Generate and wait for the process to complete.
Make sure to back up your game files before overwriting them.
Run RDAExplorerGUI.exe to extract *.rda files.
(Optional:) If you want to save your changes back to a Anno 2205 *.rda file, you must afterwards also update file.db (located in maindata), else the game will likely crash on start:
Run FileDBGenerator.exe
Select the location of you maindata directory.
You can deactivate some *.rda files, or reorder them.
Specify where to save the new file.db. Once again: Make sure to back up your original file.db before overwriting it.
Click Generate and wait for the process to complete.
Read and write version 2.2 file format (used in Anno 2205)
Choose which file version to use when saving
Known Issues
Encrypted blocks in version 2.2 files are not yet supported. When reading a file that includes such a block, there will be a short notice in the status bar at the bottom of the program. Upon saving this file the encrypted data will be missing!