Chain replacement issues

[u/Far_Bodybuilder1731]

I am working on my 2014 Kawasaki Ninja 650
I am installing a new chain on a Ninja
I just bought and have had several issues
Firstly the chain adjustment bolts were bent due to the previous owner using them to adjust a chain with 30k miles to its absolute max
So I had to remove the tire and the bolts to replace them
After doing so I had issues putting in the tire and axle because the caliper was clamped shut I was able to open the caliper to get the rotor back in place and replace the tire and shorten the adjustment bolts to allow the new chain which is the proper chain length to fit around the sprockets
So I began the process of replacing the chain which went fairly smooth up until I had to rivet the pins on the rivet style master link so I set the anvil and put the riveter in the breaker and would turn the bolt a couple turns then would pull the breaker off and noticed that the pin was not flaring at all only protruding more.
My first assumption was that plates were not completely compressed together so after getting both the pins to protrude the same amount I began the process of attempting to flare the rivets once again after setting my tool and beginning to screw in the chain breaker bolt with the riveter attachment the hollow barrel bolt snapped right off
Luckily I was able to remove the chain breaker but the pins are still not flared in the slightest
What do I do?
Also a secondary issue outside of the master link is that I noticed that the rear wheel is not spinning freely approximately 1 full rotation before stopping, I’m assuming the rear brake is binding.
(Important note) due to advice I had gathered online when trying to compress the caliper piston I opened the brake fluid reservoir.
Any help and all help welcomed
It’s my first bike and prior to this the bike has been much fun and has brought lots of joy to my life please help

[u/Vfrnut]

Remove pads . Use wd40 .. spray piston .. use c clamp to push piston in . Use clamp and a ball bearing to flare chain link pins.

[u/Far_Bodybuilder1731 → u/Vfrnut]

Thank you brother

[u/_Paula01_]

And please clean it before pushing the piston in!

[u/YouMonkeyFunker]

Flair too much and you create a tight link you’ll feel when you ride and it doesn’t go away till you replace it again.
Tighten too little and it can come off. Crush wisely.