You'll need an impact wrench capable of at least 450 ft/lbs to crush the pinion crush sleeve when setting pinion bearing preload. Re-use your old nut when doing trial/error getting the pinion depth, that way the new one wont be gutted when you go to use it for final assembly since it is a lock nut. Also don't use a crush sleeve at all when trying to get your pinion depth set until you're ready for final assembly.
Did you order a new bearing/install kit? You would need a hydraulic press and a bearing separator to remove the bearings from the carrier and pinion. Whenever you pull the carrier from the housing keep your shims oriented how they came out (left to left, right to right), sometimes you can get lucky and put them back the way they came out and have the mesh pattern set right or nearly right first try. But don't be surprised if it don't work that way since you're changing ratio.
If you ordered an install kit it should have a decent instruction manual about how pinion depth affects heel/toe of gear pattern, and depth of root (how deep the pinion tooth goes into the ring gear valley and vice versa). You'll of course need a dial indicator with either a magnetic or clamp-on stand to set backlash, and your gear set should come with info for the range to aim for, typically 0.005"-0.012" for new gears.
When setting up ring & pinion gears most people only envision the painting of the gears to check mesh pattern. But if the pattern is not right you'll need a caliper micrometer (one of those digital ones do a nice job) to measure your shims and move them from left to right or vice versa of the carrier, and change pinion depth till you get a good mesh pattern centered in the gear, well into the root but not too tight, and come out at the end with the correct backlash. You can also buy some white lithium grease in a spray can and use that to check pattern but the yellow paint in the install kits has the best visibility. Keep in mind you have to check both the "power" and "coast" sides of the ring gear teeth for proper mesh pattern.
And try to get your pinion depth and preload set before you do the final install of the carrier. The impact wrench can chip a gear tooth during that process if the carrier is in there, and it can be a longgg process with a weak impact. You'll have to take a shop rag and reach into the housing and hold the pinion's gear while using the impact, or put a pipe wrench on the yoke to hold the pinion.
Pinion bearing preload is measured in inch-pounds of rotational force of the pinion with no carrier installed. If you don't have an inch-pound torque wrench of less than 30 in/lbs best way I can describe it is spin the pinion yoke with your hand, and when you let go it will stop as soon as you let go but not be difficult to turn. For comparison, twisting off a beer bottle cap takes about 12 ft/lbs, which equates to around 144 inch-pounds. So if the manual calls for 18 in/lbs you can see it wont be much drag.
Be sure to use red Loctite thread locker on the pinion nut, carrier bearing cap bolts, and ring gear bolts which I think may be left-hand thread. Also put some silicone sealant on the pinion splines before assembly and you should have a rock-solid install.
Sticker shock I know, but here's some tools that I use or recommend:
Starrett dial indicator kit
https://jet.com/product/detail/1d0b...gtrPtANfdHIHbbepBtjkqRoClAXw_wcB&gclsrc=aw.ds
Digital caliper micrometer. One of these work surprisingly well:
http://www.homedepot.com/p/Carrera-..._6VV-yfy3EGgnIraKBRDNxoC-37w_wcB&gclsrc=aw.ds
NAPA 550 ft/lb impact:
https://www.napaonline.com/napa/en/p/NPT6767/
Proto bearing separator:
https://www.zoro.com/proto-gearbear...MkL8V1RFpv1fdKapP-QPSBoC-Qjw_wcB&gclsrc=aw.ds
This is a decent press for the price, may need to drill some holes further up the rail closer to the ram so the carrier can fit underneath. Shipping is HIGH so you may find something as good elsewhere. Of course ALWAYS use safety glasses and extra caution when using a press:
http://www.grizzly.com/outlet/10-To...hPouQoJNmOEpqESe5VdIFT3C1nLXgfOTvxBoCNeXw_wcB
Inch pound beam style torque wrench:
https://www.amazon.com/Performance-...0436&sr=1-4&keywords=inch-pound+torque+wrench
And of course you'll need a large impact socket for the pinion nut if you don't have one already but that can be picked up at a local parts store. You may be able to rent or borrow the precision tools for the job, just be very careful with them. Personally I would never loan my precision tools to anyone lol.
As with anything, shop around, try to find discount codes, etc and you can save a lot of money. Hope something here helps, good luck and post how it goes.