How to change the transmission?

First secure the vehicle on Jack stands remove both drive shafts disconnect linkage from transfer case unhook wiring from transfer case, if possible rent a transmission Jack they are equipped for also removing transfer cases do not try this alone have someone help you remove transfer case mount bolts raise transmission and transfer case with Jack under transfer case remove the cross member from the frame very slowly let the jack down about three or four inches with transfer case secure on Jack remove the bolts surrounding the back of the transmission there should be six bolts holding the transfer case on the back of your transmission when you start pulling the middle and bottom bolts you will loose transmission fluid once removed just shake the transfer case loose then pull it back lowering as you go, once done remove it from the jack readjust the jack under your transmission Jack up slightly to expose the transmission bell housing bolts use a swivel socket and long extension depending on the year older takes a 9/16 the newer ones take a 15mm break the bolts loose you may need to remove the flywheel cover remove 3 torque converter bolts again year determines size using a flywheel wrench or you can turn the flywheel using a good pair of players unplug wiring remove shifter linkage or cable from the transmission with some pressure on the jack remove all the bell housing bolts there are 6 of them and depending on weather the transmission has been out or not you may have to pry the transmission back some also watch your dip stick tube one of the bell bolts will be holding it in place remove the bolt then place a pan under the transmission to catch fluid when you pull the dip stick tube

Get yourself a service manual.