First, visit the targeted webpage and inject the following code to view realted cookie’s fields and the values assigned to them.
Second, to edit a certain value use:
For example, if the following field exist:
The value can be changed to yes with the following code:
If the field’s name does not exist, it will be created.
To have more control over cookies, refer to a proper tutorial and inject the codes in a similar way.
In addition, there are cookies editors available online such as the following PlugIn for Mozilla FireFox:
Add N Edit Cookies
Download latest release from: https://addons.mozilla.org/en-US/firefox/addon/573.