http://www.eautoworks.com/Putco-H4--9003-Heavy-Duty-Headlight-Upgrade-Wiring-Harness-PRD7540.aspx
I've not used this. Collected the link somewhere on this site.
Sorry no ideas for how to surgically apply heat. Have you tried 3 ft leverage? I've used red loctite on wheel spacer lugs plus 80 ft-lbs. No trouble taking those off when replacing shafts.
As to ratios, consider the possibility in the future you may want tires bigger than 31". I am running 33" with 4.88 ratio. Getting about 2350 RPM @ 65MPH. Very happy.
Since you said cost is a factor, consider a TrueTrac for the front and maybe even the rear. I run one in the front and a regular Detroit locker in rear. Kicked the snot out of the Rubicon; there wasn't one place I struggled for traction. It's true the the TT isn't a locker but it is VERY...