My sway bar mounts were rusted as well, I had to cut grind them off and replace with new ones. They are available at the dealership for like $20/each. This is not for the weak at heart, it's a huge pain in the a55.
This is what the sway bar mount looks like with the sway bar attached:
This is what was hidden underneath!!
Take a sawzall and get prepared to stretch into awkward positions to get it cut down to this. This took about 1 hour:
I have a 4 1/2" angle grinder (Bosch!), use that to grind the rest of the steel mount down to bare metal:
This is the new mount, grind the edges to you'll get a sweet weld on it.
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