Test your bulbs every few you install. For some reason, the wires seem to need adjustment to make good contact.

Ive noticed that sometimes the cointaker bulbs don't twist into the sockets easy. I have read that you can file down the little nubs on the bulbs to make them fit a bit better.

I just did my NGG it was a piece of cake..did it in sections. I have one finicky light at this point all others are perfect. It was pretty easy. I think it looks great for the inserts...especially the colored ones...white can be a bit bright so go with the mini's in something that might be right in your eyes

Oh looking at my video the #4 had issues before I put the LED's in...so piece of cake man do it!

i have done all my machines with them on in attract mode. Maybe i am dancing with the devil, but I haven't had a problem in 6 machines done.

The cointaker guys were working on their MM while on last year at the pinball showdown

I take my ring off and do it energized as well

Same here, I like to know that the light is working and looks good right away...plus the attract music reminds me that everything is still working correctly.

exactly, then at least i know the exact moment it wnt belly up and I can troubleshoot from there.

It's just a tiny bulb....ever change a light bulb with the power on, I might be a little more careful with the 44's

Have them on my WW. Look great and easy to install. The only issues I have are with 2 of my pop bumpers, the lights keep going out. But that looks like a socket connection issue. Oh and yes some of my PF insert light sockets needed to be moved a little and then the bulb lit up...dont fully understand how moving a socket 1mm helps but it got a connection then.

I suggest you keep the power off. Granted you are just twisting out a few plastic sockets for a good majority of it(555) but better safe that sorry. For the 44's you are going to be using a nut driver for most of those..not worth shorting something. I did a section at a time..the fired up the pin to check.

Once you short something out and have to start replacing IC chips...you won't change them with the machine on anymore...ask my friend Dave hahaha

+1 the wires seem to need adjustment to make good contact.
+1 turn the power off

I find GI bulbs that have sockets flush or just under playfield are more easily changed out by standing playfield up and removing socket from under playfield. Faster too

If you want to do it in attract mode, and don't want to risk trashing the switch matrix, just unplug the row and column connectors from the cpu board.

The only thing you really need to worry about is shorting power to the switch column drive (other things take more aggressive clumsiness, and just blow fuses).