You can do it either with command line or using GUI.
I would not recommend command line if you are not used to work with LDAP. Not that this is complex but risk is pretty high.
GUI, although risk is high too, permits better control. However, take care not to change any value you do not clearly understand !
LDAP GUI choice:
Google is your friend here. There is a lot of different LDAP admin tools. This is mainly matter of choice.
You can also have a look
here.
One not in this list but very easy to use (although no more published but you may still find it somewhere: java based ldap admin tool from ...
Apache Directory is quite good too. Jxplorer is ok... well, a lot of choice.
Once you have installed interface of your choice, then connect to cn=config (based DN) on port 390 (using cedential you will find in Users& Groups section/ ldap setttings, and look at attribute "olcloglevel". Change default value ("0") to "256" and look at result in /var/.log/syslog.
As this is very verbose, keep in mind to revert back to "0"
I hope this helps.