Simply unzip the distribution somewhere. Linux/Mac example:

~$ cd /opt
/opt$ unzip /tmp/xfc-4_3_2.zip
/opt$ ls xfc-4_3_2
bin/
doc/
legal.txt
legal/
samples/

This means that uninstalling XMLmind XSL-FO Converter simply consists in deleting the directory created by unzipping its distribution.