Is a Pinion Bearing replacement in B 4000 1998 differential a costly job?

Is a Pinion Bearing replacement in B 4000 1998 differential a costly job?
Yes it is, besides pulling both axle, you have to remove the entire carrier assembly before you can remove the pinion shaft. I recommend you go to a good public library and take a look at the automotive books they have and check out the pictures and procedures to R/R the pinion bearings. Oh did I forget to mention you need a good long punch to drive out the old races in the housing and need to have the bearing on the pinion pulled off and a new one pressed on. Be sure to keep any shims on the side bearings in order as to not mix them up side to side or your clearances on the ring and pinion will get messed up. Mark the pinion nut with a center punch on the nut itself and the end of the pinion shaft so you can line them up during the assembly process. Line up and go past about a quarter inch or if you want you can check drag per instructions in the repair manual. I find marking it is easier and works fine if you didn't have a loose gear to gear clearance problem. Be sure to torque all bolts to specs and use blue lock tite to the threads. If you have doughts about doing the job, please seek help or take to a qualified shop. Making a mistake could be costly. Ring and pinion sets can be $200 to $400 and up. Good luck. John , Tacoma, Wa