I am going to install a front dome light sometime and don't know the best tool to cut the headliner with. I don't plan on taking the headliner out. I'm going to make a template from the center dome light and test it with some cardboard before I cut into the headliner. I was thinking about drilling a starting hole with a small drill, then just using scissors. Surely there is a better way?

 

When I was messing around with the rear dome light, I noticed that the headliner seemed very thin but sturdy. I'd say you'd probably be able to make a nice clean cut with a box cutter or anything else with a razor blade. Scissors might work but since your not taking the headliner out, it might be awkward to use them. As always, measure twice, cut once.

 

a brand new razor blade is all you need

 

Here is a tech article on dome lights. The author used a single edge razor. (They actually used those to shave with even before MY time LOL)
https://www.scionlife.com/forums/viewtopic.php?t=41308

 

OK thank you.

Know where to get a OEM dome light for less than $32?