You can put a VB in it with the trans still in the truck. Anything else requires pulling it. The TC is pretty simple to replace once the trans is pulled. You don't have to take the trans apart for that. If you don't have a service manual you REALLY should get one!!
I see in your signature that you have a mystery switch. How is yours wired? There are two ways: with a single throw single pole switch (on and off) or with a double throw single pole switch (on, off in middle, and on). The first way allows you to force a lock or use normal operation. The second allows a forced lock, forced unlock, and normal operation.
The second way is better because the TCC may be destroyed by hard pulling or hard excelleration with the TC locked. Actually, this can occur with the normal stock operation if the TCC doesn't kick down (unlock) in these conditions.
Mine is wired the second way with a push button mounted on the floor to interrupt the ground wire easily for stopping or down shifting.
You should be aware that our transmissions are different than later models. From '96 on these trucks have a 47RE transmission. The '94 and '95 have a 47RH. Basically our governor pressure is controlled with a fly weight governor while theirs is controlled by the CPM with a solenoid.