Adding on to Thumper's excellent post.
I have ordered all the tools to grind off the blind break off bolts.
Of course waiting for the my wife to get back with the car so I can go get some replacement M4-.7x16mm socket head bolts to put in after they are out I decided to give it a go with my old fashioned way to pass the time.
What a success that was!
I used my hacksaw and cut a slot deep into the first break off bolt. Using thumb and finger to align the blade and just kept draging it non cutting across the top until I had the smallest of purchases, then a tiny push forward and it slowly opened a the beginning of the slot. I then cut down deep.
I had a kit of screw ends, typical phillips, torx and flat head for some tool but never used them. They gave me three different sizes of flats.
Without the tool I just grabbed a small adjustable wrench and sized it to fit the hex shank. I then inserte the smallest into the slot as the others wouldn't fit all the way down.
Pushing the bit down with my thumb and weight I very slowly turned the adjustable wrench. I felt the bolt melt smooshing ever so slightly and as I kept the pressure on and watching I saw movement. I kept moving it slowly and the pressure slowly smooshed the metal more.
Once the metal was opened slightly I moved up to the next sized flat blade bit and continued. I ended up going through all three sizes and finally the bolt was out! -- happy dance!
Now for the second.
Repeating the hacksaw start on this one but it slipped. I repositioned and tried again. Slip. Slowed down and tried again and got a bite. When I removed the hacksaw to inspect the beginning of the slot. Dismay! -- I cut it offset from center ever so slightly. I just made my job that much harder.
I cut the slot down deep and then repeated the process of smallest flat blade and going up as the metal smooshed. The bolt did not move on the smallest blade, only smooshed. Oh no!
I moved up to the second blade and it started smooshing and I thought I was finished and had to wait until the tools arrive on Saturday to grind it off. But it suddenly moved a millimeter. I could tell from the force needed this wasn't going to end well.
But I managed to get it to move 90 degrees before it accelerated on the smooshing and stopping on the moving the bolt. I took this time to cut a second hacksaw slot in ala Phillips style. It was worth a gamble. At the rate of smooshing and little movement I was at failure point with the first slot.
I took a small lightweight hammer and tapped a regular sized flat blade screwdriver into the first slot to open up the center of the slot to allow a bigger blade.
I then worked the new slot with the smallest flat blade bit and worked up. More smooshing, more work than the first bolt due to off center slot but I got it to move a little more out.
The rest was lightweight hammer and regular sized flat blade to open the center on the second slot then very slow turn with pressure down and as it smooshed switch slots and tap down and repeat, as that smooshed switch slots and tap down to open up.
Finally I have success!
Photos to see the bolt that gave the grief. Now I am off to the hardware store for new replacement bolts.
and detail of the top of the bolt after smooshings after both cuts
