I want to replace my interior light bulbs with leds too. I saw Precision Led on YouTube and they have a kit with the leds and tools to use. Their instructional videos are good. Not sure what year your 4runner is, but here's the link for a 2013 led kit from them. Toyota 4Runner LED Interior Package (2009-Present)
i just bought a kit from these guys. the dome light doesn't work/fit, half the courtesy bulbs don't work and one of the rear cargo lights don't work
they are 0% brighter than the stock bulbs, just whiter
haven't emailed them but kinda bummed.