Changing texts in templates

Hi. Just wanted to know. For an installed version of the system, is there a way to actually update the template text? For example, I would like to update the following:

Welcome to Indico. The Indico tool allows you to manage complex conferences, workshops and meetings. > To start browsing, please select a category below.


Welcome to Conference portal. Please register using the log in button above. If you do not receive, registration email, please check the spam folder.

This particular text can be changed by editing the root category and setting a category description there.