Force-load a custom CSS file to override particular CSS elements on a certain website?

Is this possible through creating your own Firefox/Chrome add-on?

For instance, instead of some of the default elements that point to images, I’d like to point them to a different image… or change the color(s) of some text, and backgrounds…

I have the ability to create the CSS, but I have no idea how to force-load, or override what loads by default.

Any help you can provide would be greatly appreciated

Not sure if it still applies though.

Is this possible through creating your own Firefox/Chrome add-on?

For instance, instead of some of the default elements that point to images, I’d like to point them to a different image… or change the color(s) of some text, and backgrounds…Appvalley

I have the ability to create the CSS, but I have no idea how to force-load, or override what loads by default. Tweakbox

Any help you can provide would be greatly appreciated
issue solved!!!