I am changing the starter and would like a diagram of it to facilitate its removal.

The key lock cylinder operates the ignition switch sometimes ignition switch is separate sorry I didn't find where ignition switch is located if the lock cylinder is plugged into it.
You should have a starter relay and starter relay fuse.
This diagram of starter circuit shows the clutch pedal switch in the circuit on an automatic should have the neutral safety switch in the circuit. This is for 95 Rodeo.
Stater Motor Circuit Diagram (1995-1997 2.6L Isuzu Rodeo) (easyautodiagnostics.com)

How do I remove the key ignition cylinder? ' Isuzu SUV Forum (planetisuzoo.com)
Isuzu Trooper Ignition Switch Replacement ' Cost & Service ' RepairSmith
Changing the Ignition Lock: Changing the Ignition Lock, Safley ... (2carpros.com)
Starter and solenoid
Isuzu Trooper Starter replace under 1 Hour - YouTube
Isuzu Trooper (1995 - 1996) - fuse box diagram - Auto Genius
Starting System & Wiring Diagram - YouTube

Depending if you have the Reg, sport, or high end like overland you may have to remove the subframe to facilitate getting it out

yes you can if you have some knowledge .
disconnect battery making sure you have radio codes before disconecting
take picture of wiring with camera phone if possible on starter or mark position and write down
remove wiring
mark starter position that is starter to housing to facilite installation of new starter
remove bolts from starter normally 2 or 3 bolts holding it in position
remove and fit in reverse order

if you are going to change the starter conferm that is the problem begin by removing the negitive cable on the battery pull parking brake raise car if in dought on wire removal reinstalation draw makeshift diagram.bench test starter when removed for confermation of problem.

when i try to start my starter clicks

remove the serpentine belt by taking the tension off of the tensioner pulley. do this with a serpentine belt tool. you could also use a 3/4 drive ratchet or 3/4 breaker bar. insert the 3/4 drive into the square drive hole. while facing the front, angle the ratchet as far to the left as possible. remove tension by pulling to the right, remove the belt from the alternator.(note) if there is no diagram of belt routing, make one yourself to facilitate installation. remove the connectors from the alternator, remove 3 bolts, remove the output cable. check the other pulleys for wobble. the tensioner should be replaced, especially if the arm doesn't move smoothly through the length of travel

Rear of drivers side of engine. Will probably have to remove left bank exhaust downpipe to facilitate starter removal.

NOTE: Some Toyota models have an access plate in the fender well to facilitate starter service. Check for such an access point before beginning starter service.

1. Disconnect battery ground cable. Remove battery, battery tray and/or igniter bracket, if necessary.
   1. Disconnect electrical connectors from starter motor.
   2. Remove air cleaner assembly, if necessary.
   3. On models with automatic transmission, remove transmission oil filler tube if necessary.
   4. Remove starter motor attaching bolts, heat shield (if equipped), then the starter motor.
   5. Reverse procedure to install.

I just changed my starter recently, when you look at the starter its in a very tight spot. Loosen the transmission lines running right under the starter. As your laying under your suv you will see 2 lines running right under your starter, just follow the 2 lines toward the engine and you will see a small bracket that holds them together. Losen the screw and wala you now have several inches of play now that u you can move the lines out of the way, this will grant you ease in getting the starter in and out. This was my first time changing my starter and i had the car for 11 years ^_^ I changed it in 2-3hrs remember to disconect your battery also before you begin ^_^

Your best diagram is the starter itself...make notes on where wires are attached and what you removed from where. Always remove the positive cable from battery before you begin and never allow wires on one starter terminal to touch ones from adjacent terminal when you replace them.
Remember...your starter turns the engine so it can start...it does not start your engine. Always have your battery charged and load tested to avoid changing the starter because the battery is bad.