73 Chevy 3/4 4X4

I have the stock front end with spicer hubs that have developed a problem with freezing in cold temps. Either one or the other wont lock in correctly, Have worked on before.  Have brand new set of Warn hubs that I would like to replace.  Step 1 is to remove existing hubs.  Book says to jack up vehicle and have to remove piece by piece with snap rings/etc.  The new Warn ones look like just bolt-on units.  So can I do the exchange with tires on ground?  Prob is Im stuck on road on snow/0 deg temps and cant get to a garage.  Thanks for any help  

Sound like you have too much grease in hubs. This is kinda a classic problem. You need to pull hubs and take them in where it is warm and remove all excess grease from them. You want them with just a very thin film of grease over gear/clutch parts in hubs.  Some pack these with grease and then it get cold and grease gets stiff and hubs do not work. You can wash them out with kerosene if they are really gummed up and then apply a VERY thin film of fresh grease to working parts.  

thanks snowman.  Think the person that took them apart did put too much grease in them,. They have been too trouble-prone, is why I want to put the Warn ones on.  But my problem is I cant remember if the old ones come off as one piece or do you have to dis-assemble 1 part at a time like the chilton book says?  And if I can do that with truck on ground, because I cant really jack it up out in the snow bank right now?  

Most hubs have one side of dog clutch attached to axle and the other in hub. No need to jack it up as they come right off. Pull hub and clean all the grease out  and slap it back on and get truck out and then you can inspect more later.