Open the logo-source.png file in Adobe® Fireworks.
Focus on the right column, titled Layers. Select the Web layers directory and click the eye icon to the left of the logo slice (the green object). This will make the slice invisible so you can edit the file.
Step Two: Text/Slogan/Icon Editing
Double click on the logo text. Now you can edit the text of logo to your choosing.
Now, select and disable the icon if necessary. Or replace with an alternative vector.
Step Three: Slice Modification
Reactivate the Slice in the Web Layers column, this will place a green rectangle over the logo image. Change the size of the slice (or move it) to match the new size if applicable.
Step Four: Export
Now you will want to export the logo. Right click on the image slice and select Exported Selected Slices... from the contextual menu. Proceed to export it to your computer for uploading.
Step Five: Multiple Frames/States
If there are multiple logos for a template, they are located in Frames or States within Fireworks.