If the hole drilled into the dash panel is the right size, they just push in. Hook one wire to ground and the other I spliced into the appropriate factory wire that goes (or used to go) into the round plug in the back of the stock dash panel.
If I did it again, I would order the 0.125 diameter LED for the blue brights indicator. It seems a little too bright sometimes. I like the 0.312 diameter LEDs for the other stuff though.
