I would suggest looking into LED light pipes (or light guide) it's basically a lens or hard fiber optic that is used commonly in electronics to have light shine from an LED on a board to the front panel. They are commonly used for power lights on the front of computer cases and home theater amplifiers, and generic ones can be bought from many electronic stores. If you can find the shape/size you need in bulk, they are quite cheap, about the price of a small bolt. You can make them as well, and many you can either cut to length or heat up and bend.
Otherwise you can unsolder the LEDs and attack leads if you're up for it, it's a little finicky though. I imagine you could run LEDs in parallel with the existing ones as well if they're low enough power but that would be well beyond what routerboard/mikrotik would support.