Yes, You can put a manual shift valve body in it.
Automatic or manual trans?
If it is a manual trans, the shift linkage might be loose, bent, or damaged.
A His and Her shifter is where you can go from an auto shift to a manual shift with out having to change trans. and things like that.
On top of the shift housing on the very top of the trans. Has 2 wires into it 7/8 wrench to remove
If you remove the access panel you will see where the shifter is bolted to the top of the trans, remove the 4 bolts holding it on and it will pull straight up and out.
yes, for most repairs
On top of the trans close to the firewall and engine block. Look where the shift cables (manual trans) come out of the firewall.
If this is a standard shift transmission, some one may have put the incorrect trans fluid in to it. Drain and refill with correct fluid, check your drivers manual for correct trans fluid.
Remove the linkage off of the trans and shift it there.
on most gm stick shift trans there is usually a plug nut on the side of the trans that requires a 3/8 ratchet and some times a short extension to remove it fill with 90 weight gear lube till it runs out of the hole it is full
If it is just the shift knob you want it will turn off ( there may be a jam nut at the bottom to loosen first ) As for the entire shifter, remove the shift knobs, boots, carpet, and the two metal panels at the floor, then remove the 2 bolts and 2 nuts at the top of the shifter housing, then remove the bolts on the side and back of the 4wd shifter bracket located on the drivers side of the trans, once that is done you can kinda move it out of the way without removing the linkage. Now you have access to the 2 bolts on the drivers side of the housing, remove those and the shifter assembly will pop right out.