Quoted from LTG:Please forgive me for pointing this out. The time you spend researching this. Figuring what you need. Ordering parts. etc. etc.
You could have sat at a table for 5 minutes and learned to solder better. Heat joint, touch solder to joint, watch it flow. Done.
LTG : )
No, don't ask for forgiveness. This is pure truth. If you're going to own pinball machines, you need to know how to solder. It's like playing basketball without knowing how to dribble or shoot.
Bite the bullet, practice some, and learn a basic skill of this hobby. As stated, at least hundreds of videos on this. Get some "solder flux" to help you at first, and with time, you'll get the hang of it, and it will become second nature.