You'll find a photo on Zitt's instructions for his laser upgrade mod...

http://pinball-mods.com/blogs/wp-content/uploads/2016/04/Pinball-Mods.com_LaserInstall.pdf

I did an upgrade video of the laser years back in my Prem. I updated to an CoinTaker laser. Don't know if the pics or vid can help you out.

Blog Post
https://pinballsupernova.wordpress.com/2015/11/24/mod-install-cointaker-laser-upgrade-for-star-trek-leprem/

WebSite
http://www.pinballsupernova.com/star%20trek%20laser%20mod.html

YouTube Video

meh...I'm sure many folks will like it, but I personally don't care for it; not sure why...maybe its just that green lasers is more of a Star Wars thing.

I'm actually probably going to be committed as I'm thinking about adding a second laser to my LE... and the color would be Yellow.
And no... Yellow lasers ARENT cheap by any stretch of the imagination.

Someone talk me out of it - Please!

The problem is that the Pro code DOES NOT control the proper transistor to fire the laser model.
Your going to have to hack the source code in the rom... assuming that transistor hasn't been used for something else.
I'm unaware of anyone actually doing this.

I'd do a blue laser if they weren't so expensive.

Blue is expensive because the source diodes are expensive. My lasers require a waiver... because of the power output- that's why they'll likely never drop it price. I'm actually thinking that when I run out of stock; they'll go end-of-life.