No special actions are needed, just stop any running HService and HControl and copy the new files over the old ones. All configuration and data files are preserved this way.
Data files and directories are compatible, so no special action is needed here when updating.
System configuration (service, autostart group, icons etc.) needs to be changed to use the new programs HService.exe and HControl.exe instead of the old Hamster.exe. It's suggested to remove the old entries for Hamster.exe completely (including removing/renaming Hamster.exe itself) before reconfiguring all for the new ones.
It's suggested to start from scratch, i. e. do a fresh Installation in a separate directory. At least make a full backup of the complete directory of the previous Hamster version.
You may also try the approach for Playground 1.0 versions (see above), but it is strongly suggested to additionally open all configuration forms in HControl and save all of them with the OK button once. This makes sure, that all settings are saved in Playground's data format.
[www.elbiah.de Hamster Playground Documentation]