If you are at all worried about breaking the mirror, Rock Auto has replacements.
For $90/each you can get the mirror assembly with lights built in and with a factory look. They bolt in easily & come in paintable black. With less risk of damaging your existing mirror, you can sell your old ones to help cover the cost of the new ones.
Parts on the mirrors from Rock Auto are not interchangeable with the factory mirrors - they are slightly different. But as Alex1a1f suggests, I wouldn't be surprised if the mirror wiring harness has the light wiring in place. Why not make it look factory? Considering your labor in modifying, it might be worth it.
View my fuel log 2015 Mirage ES 1.2 manual: 48.7 mpg (US) ... 20.7 km/L ... 4.8 L/100 km ... 58.5 mpg (Imp)