Water leak from sunroof 1990 Seville

With the sunroof open there are two drains on either side at the front.
One is blocked. I have tried "rodding it through" but to no avail.
Any advice on how to clear the blockage.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.