1). Just download the distribute archive [Kernel or BASE is mandatory for Productive version], and expand (unzip) it into desired (non-root!) directory.
2). Download additional plugin pack(s), if needed. Put desired plugins into Plugins folder. Free trial version doesn't use plugins.
3). Run CheckLog.exe with demo database, or create CheckLog.mdb file automatically during the first run (folder DB must be empty before the run).
Don't forget ask for activation key, if you need it for kernel. All plugins connected to the kernel do not require activation.
Remember: free trial version doesn't need activation keys at all.