I believe 4.56 is as low as you can go in that truck, and if so that I the ratio I would recommend with 37's.
It is a fairly involved job and requires pressing on bearings, shimming the gear set to get the correct backlash and tooth contact pattern, and torquing everything correctly. There is a decent amount of work just to replace the gears, especially in the front, and then the part about making sure they are setup correctly. If they are not setup correctly you risk excessive wear, noise, and possibly early failure of the gears. Not trying to scare anybody away as with doing some research, having access to the correct tools, and taking your time it can be done. Just don't expect to do it in an apartment parking lot with a Harbor Freight wrench set on a Thursday night after work (....that comes from a YouTube video of somebody doing gears on their truck.....I cringed the whole time as they used a hammer and chisel to remove bearings and never checked the setup of the gears!).