How to uninstall pagespeed

[LotsOfQ]

I've installed

yum install mod-pagespeed-stable --enablerepo=*page* -y

Then learned that it's incompatible with Piwik. On their site said:

You may disable pagespeed for Piwik by adding this to the apache config: ModPagespeedDisallow "path_to_piwik_here"

But I don't know how to add that to apache config. So I think I will just uninstall pagespeed.
How do you uninstall it?

[MRatWork]

Pagespeed already enable after installed. Only need optimize their configuration in /etc/httpd/conf.d/pagespeed.conf.