So my starter motor gave up on me. Should be no big deal was my thought as i have the service manual and good tools. This is what I went through to have it fixed, starting from troubleshooting to getting it changed.

CONVENTIONS IN THIS DIY
I'm from Europe so we use the metric system and tools. I'll refer to the tool size in mm (about a 24th of an inch) using # such as nut #8 and will indicate correct inch sizes when mm tools won't work such as 1/2" wrench. Have yet to come up with an equivalent table for approximations between inch and mm tools. Some tool sizes work very well while others do not properly fit.

TROUBLESHOOTING
Starter acted up on me about 2 years ago for the first time. Simply would not crank and no click from the solenoid. Tried several more times and it came to live again. Then about 4 months ago the same. Had to jumpstart from another car, then came back to live to last 4 more months. Now it quit completely. No way to have it turn. So this is the "No cranking, no sound from solenoid". Interesting enough that the service manual goes throug: Check battery voltage. Check cranking voltage at battery posts. Check voltage from engine block to battery negative post, key in starte position, voltmeter positive lead on block (to be o.k. should be < 0.5 V). Check cranking voltage at starter "B" terminal. (purple cable - the small one).
The emissions and diagnostics manual sends you through the fuse box and all the connectors.

To get it short: Go directly to the starter motor. Measure voltage on the purple cable to the starter motor. Work through wheel well and plastic flap at rear of suspension. Use a long lab clamp to get there. With cables long enough you may be able to put the voltmeter on the outside of the windshield to check it while sitting in the car. Voltage above 9.6 V should be o.k. (Mine was)

So: starter motor or solenoid broken - replace starter motor

PROBLEM SOLVING
Ordered a new one from rockauto and got an AC Delco (new) motor which is a treat! More later.

Disconnect battery negative terminal
Lift truck and remove front right wheel. If possible use garage lift or yack stands.
Through the wheel well pushed the plastic flap in and upwards out of the way.
Using small ratchet with #13 nut unscrew the thick cable from the battery. Connector towards outside of car.
Using small ratchet with #8 nut unscrew purple (small cable) from starter switch. Connector towards block.
See picture DSC04074_s.jpg

If equipped with skid plates remove the skid plate. May need a TORX 40 depending on the bolts.
Using med/big ratchet with #15 nut unbolt the 6 bolts on the converter housing cover. (Service manual does not refer to it but on mine it had to go off! This cover is sometimes also referred to as "inspection cover" or "flywheel cover".)
The 2 rods can be moved a bit downwards enough to get the cover down 5 cm (2") or you have to get them loosened at the block to get the cover out completely.
Using med/big ratchet with #15 nut unbolt the two long bolts holding the starter motor
See picture no. 2 (The bolts are already out in the picture)

TROUBLE
Without removing the cover there is no way that an original starter can be removed. It gets stuck to the upper part of the block, 4x4 suspension bracket and the rod and the engine mount.
See picture no. 3 (The red circle shows where the starter motor touches)
See picture no. 4 (The starter motor cannot be slid out of the opening in the bell housing. (Actually the cover - yes I tried without getting it off...)
To get bolt no. 6 out of the converter housing cover use a special wrench with a joint to work around the front axle shaft or remove the shaft.
Careful, the caps held in place by the clamps are actually the needle bearing outer rings. They fall apart easily as I had to learn. Still need to get them back in. They are back in and they contain each 31 needles...
See picture no. 5

IF IT WORKS PROPERLY
Remove the starter motor by pushing the back of the starter upwards and turn a bit until it comes down.
If you get the same replacement as I did, you may as well put everything together now before putting the starter motor back in as it fits now.
See picture no. 6
Else put the starter up with the back pointing up. Through the wheel well fix the cables back to the terminals.

WORKAROUND FOR STARTER MOTOR CABLING
I've considered fixing longer cables to the motor. As I now have a starter motor which is readily removed I left it as is. Putting longer cabling could be helpful if the Blazer is used heavily offroad and starter replacements are a common occurrence.

Put the converter housing cover back and fit the starter motor in at the same time.
Put the rods back in place and fix with bolts. Torque the rods on the block if loosened before.
Check that the cover properly sits and torque the 6 bolts back on. (No torque given in the service manual)
Now it would be time to put the front drive shaft back on very carfully, 2 persons might even be better and torque the clamps. (37 Nm - 27 lbs ft.)
Put the two long bolts back into the starter motor and torque to (43 Nm - 32 lbs ft.)
Battery cable back.
Check if working! Careful if still sits on jacks or on the lift.
Pull the flap back into place.
Mount front wheel.
Done. Gone for a looong shower. Had dirt up to the shoulders as I had to work on the garage floor. No jacks, no stands.

 

nobody told my starter it was too big to squeeze out, cause it did without removing anything extra (torque conv cover & front shaft). Not a bad write up tho

 

Nice, i was able to get mine out without removing anything as well.

 

Lucky you!

IMHO it depends on which combination of starter motor and engine version with 4x4 you have.
I hope it helps those of us with the same problem.