CMLCA is free to use. However, note that it is "empty": it does not contain any data. You can obtain CMLCA with data in different ways:
by purchasing or downloading databases that can be imported into CMLCA. Examples of such databases are ecoinvent's database, JRC's European Reference Life Cycle Data System (ELCD), NREL's U.S. Life-Cycle Inventory Database, EXIOBASE, the multi-region environmentally extended IO-databse from the EXIOPOL project, and CML's database of impact assessment factors (CML-IA).
by purchasing a copy of CML's European Environmentally Extended Input-Output Tables (E3IOT).
by importing data that have been produced by other programs using one of the exchange formats.
Read CMLCA's license conditions before downloading the program.
CMLCA's system requirements are modest. A standard PC with 64 bits Windows is good enough. An internet browser is needed to read the manual. Excel is needed to export data and results to Excel format.
You can download CMLCA from the dedicated download page.
Once downloaded and saved, use an archive program (such as WinZip) to unzip cmlca.zip to a convenient location (such as C:\User\Program Files\CMLCA\). This will create a number of files (the program, documentation, and some demo projects). You may wish to put a shortcut on your desktop or the quick launch toolbar. After unzip, you may remove the zip file.
Newer versions of CMLCA may just be placed over the existing one.
As CMLCA is not really installed, you don't need to deinstall it either. Just removing the entire folder where you have unzipped the files to suffices.